# LEGO 7721-1 — Combat Crawler X2 (2007)

Source: https://www.brickmissing.com/sets/7721-1-combat-crawler-x2
Publisher: BrickMissing (https://www.brickmissing.com) — free LEGO parts checker. Not affiliated with the LEGO Group.

The EXO-FORCE faces a formidable threat with the Combat Crawler X2 (7721-1), a 2007 release from the Exo-Force theme. This menacing machine operates as two distinct battle units, presenting a dual challenge on Sentai Mountain and within the Golden City. In its combined configuration, the crawler boasts multiple clawed legs for traversing difficult terrain, incorporating a prison capture cage for enemy combatants. A powerful firing cannon, featuring a spring-loaded Technic missile, is mounted prominently for long-range assaults. When direct engagement intensifies, its front section detaches, transforming into an autonomous robot battle machine. Ryo, equipped with his own missile-launching strike flyer, must confront both elements of this advanced menace, employing hinge plates for his flyer's wing articulation to evade attacks.

## Set facts

- Set number: 7721-1
- Name: Combat Crawler X2
- Theme: Exo-Force › Golden City
- Released: 2007
- Pieces: 581
- Distinct part + colour lots: 156
- Build difficulty: intermediate
- Repairability: 3.2% of this set's lots are hard to replace (5 of 156 part+colour combinations appear in three or fewer sets in the entire LEGO catalog).

## Complete parts list (156 lots, 581 pieces)

Prices are the official LEGO Pick a Brick price per individual part, where LEGO publishes one.

| Qty | Part | Colour | Part no. | LEGO element ID | LEGO price each |
| ---: | --- | --- | --- | --- | --- |
| 2 | Tile Special 1 x 2 Grille with Bottom Groove | Light Bluish Gray | 2412b | 4211350 | €0,06 |
| 3 | Tile Special 1 x 2 Grille with Bottom Groove | Black | 2412b | 241226 | €0,06 |
| 7 | Plate Special 2 x 2 with 1 Pin Hole [Split Underside Ribs] | Dark Bluish Gray | 2444 | 4196768 | — |
| 1 | Plate Special 2 x 2 with 1 Pin Hole [Split Underside Ribs] | Black | 2444 | 244426 | — |
| 2 | Plate 2 x 12 | Dark Bluish Gray | 2445 | 4211067 | €0,36 |
| 2 | Brick 2 x 6 | Black | 2456 | 4181144 | €0,29 |
| 8 | Brick Special 1 x 2 with Pin | Dark Bluish Gray | 2458 | 4211087 | — |
| 3 | Plate Special 1 x 2 Side Handle [Free Ends] | Yellow | 2540 | 4140587 | €0,07 |
| 4 | Plate Special 1 x 2 Side Handle [Free Ends] | Black | 2540 | 4140588 | €0,07 |
| 2 | Technic Disc 3 x 3 | Black | 2723 | 4218868 | €0,21 |
| 33 | Technic Pin with Friction Ridges Lengthwise and Center Slots | Black | 2780 | 278026 | — |
| 4 | Technic Beam 1 x 4 Thin with Stud Connector | Black | 2825 | 6331570 | €0,21 |
| 2 | Lever Small Base with Black Lever | Yellow | 298c02 | 74156 | €0,19 |
| 4 | Technic Brick 1 x 2 - 1 x 2 Angled with Bumper Holder [Closed Front] | Black | 2991 | 4114238 | — |
| 2 | Brick 2 x 4 | Black | 3001 | 300126 | €0,22 |
| 1 | Handlebars | Light Bluish Gray | 30031 | 4258308 | €0,10 |
| 1 | Brick 1 x 2 | Dark Bluish Gray | 3004 | 4211088 | €0,11 |
| 3 | Brick 1 x 2 | Black | 3004 | 300426 | €0,11 |
| 4 | Brick 1 x 1 | Black | 3005 | 300526 | €0,07 |
| 3 | Fence Spindled 1 x 4 x 2 [2 Top Studs] | Dark Bluish Gray | 30055 | 4256495 | — |
| 1 | Brick 1 x 6 | Light Bluish Gray | 3009 | 4211393 | €0,25 |
| 2 | Plate 2 x 4 | Light Bluish Gray | 3020 | 4211395 | €0,15 |
| 2 | Plate 2 x 3 | Red | 3021 | 302121 | €0,13 |
| 6 | Plate 2 x 2 | Dark Bluish Gray | 3022 | 4211094 | €0,10 |
| 1 | Plate 2 x 2 | Red | 3022 | 302221 | €0,10 |
| 4 | Plate 2 x 2 | Light Bluish Gray | 3022 | 4211397 | €0,10 |
| 2 | Plate 2 x 2 | Black | 3022 | 302226 | €0,10 |
| 2 | Plate 1 x 2 | Black | 3023 | 302326 | €0,08 |
| 7 | Plate 1 x 2 | Yellow | 3023 | 302324 | €0,08 |
| 9 | Plate 1 x 2 | Light Bluish Gray | 3023 | 4211398 | €0,08 |
| 2 | Plate 1 x 1 | Trans-Red | 3024 | 6513963 | €0,06 |
| 2 | Plate 4 x 4 | Dark Bluish Gray | 3031 | 4243831 | €0,21 |
| 1 | Plate 4 x 4 | Black | 3031 | 4243819 | €0,21 |
| 4 | Plate 2 x 8 | Dark Bluish Gray | 3034 | 4210997 | €0,29 |
| 4 | Plate 4 x 8 | Black | 3035 | 303526 | €0,46 |
| 1 | Arm Mechanical with 2 Clips [Battle Droid] | Light Bluish Gray | 30377 | 6319333 | €0,13 |
| 2 | Slope 45° 2 x 3 | Black | 3038 | 303826 | — |
| 1 | Slope 45? 2 x 2 | Yellow | 3039 | 303924 | €0,11 |
| 1 | Slope 45? 2 x 2 | Dark Bluish Gray | 3039 | 4211054 | €0,11 |
| 4 | Technic Link 1 x 5 | Black | 30397 | 4140701 | — |
| 2 | Hinge Plate 1 x 8 Locking with Angled Side Extensions, Rounded Plate Underside, 9 Teeth | Yellow | 30407 | 4124433 | — |
| 2 | Brick Special 1 x 4 with 4 Studs on One Side | Black | 30414 | 4162443 | €0,18 |
| 2 | Slope 45° 2 x 1 Triple Smooth | Black | 3048b | — | — |
| 1 | Turntable 4 x 4 Locking Grooved Base | Light Bluish Gray | 30516 | 4296249 | — |
| 5 | Brick Special 1 x 2 with 2 Pins, Round Pin Holes | Light Bluish Gray | 30526 | 4211660 | — |
| 2 | Brick Round 1 x 1 Open Stud | Light Bluish Gray | 3062b | 4211412 | €0,06 |
| 1 | Turntable 4 x 4 Top, Locking | Black | 30658 | 4142915 | — |
| 1 | Tile 2 x 2 with Groove | Black | 3068b | 306826 | €0,07 |
| 1 | Tile 2 x 2 with Groove | Dark Bluish Gray | 3068b | 4211055 | €0,07 |
| 1 | Tile 1 x 2 with Engraved Code for Exo-Force | Yellow | 3069bpr0073 | 4500833 | — |
| 1 | Technic Brick 1 x 2 [2 Pin Holes] | Red | 32000 | 4179355 | €0,10 |
| 2 | Technic Plate 2 x 6 [5 Holes] | Yellow | 32001 | 4107750 | — |
| 2 | Technic Beam 1 x 11.5 Double Bent Thick | Dark Bluish Gray | 32009 | 6271155 | €0,39 |
| 4 | Technic Beam 1 x 11.5 Double Bent Thick | Light Bluish Gray | 32009 | 6271156 | €0,39 |
| 16 | Technic Axle and Pin Connector Angled #1 | Dark Bluish Gray | 32013 | 6296856 | €0,08 |
| 4 | Technic Axle and Pin Connector Angled #5 - 112.5° | Black | 32015 | 6271346 | €0,21 |
| 6 | Technic Brick 1 x 14 [13 Pin Holes] | Black | 32018 | 4107558 | €0,56 |
| 2 | Technic Axle Connector with Axle Hole | Black | 32039 | 3203926 | — |
| 1 | Technic Axle Connector with Axle Hole | Light Bluish Gray | 32039 | 4211553 | — |
| 6 | Technic Pin Long with Friction Ridges Lengthwise and Stop Bush [3 Lateral Holes, Big Pin Hole] | Red | 32054 | 4125198 | — |
| 8 | Technic Axle 2 Notched | Red | 32062 | 4142865 | €0,07 |
| 8 | Technic Brick 1 x 2 with Axle Hole Type 2 [X Opening] | Black | 32064b | — | — |
| 1 | Technic Brick 1 x 2 with Axle Hole Type 2 [X Opening] | Yellow | 32064b | — | — |
| 7 | Technic Brick 1 x 2 with Axle Hole Type 2 [X Opening] | Dark Bluish Gray | 32064b | — | — |
| 5 | Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced | Light Bluish Gray | 32123b | 6271165 | €0,04 |
| 1 | Technic Axle and Pin Connector Perpendicular 3L with Centre Pin Hole | Black | 32184 | 6276951 | €0,12 |
| 8 | Technic Driving Ring Extension, 4 Ridges | Light Bluish Gray | 32187 | 4209329 | — |
| 2 | Technic Beam 1 x 9 Bent (7 - 3) Thick | Red | 32271 | 4141743 | — |
| 1 | Technic Axle and Pin Connector Perpendicular Double | Black | 32291 | 6280394 | €0,15 |
| 6 | Technic Beam 1 x 5 Thick | Black | 32316 | 4142135 | €0,19 |
| 1 | Technic Beam 1 x 7 Bent (4 - 4) Thick | Light Bluish Gray | 32348 | 6278129 | €0,27 |
| 2 | Brick 1 x 2 x 2 with Inside Axle Holder | Dark Gray | 3245b | 4206827 | — |
| 3 | Technic Beam 1 x 3 Thick | Yellow | 32523 | 4153707 | €0,10 |
| 2 | Technic Beam 1 x 7 Thick | Black | 32524 | 4495935 | €0,25 |
| 6 | Technic Beam 1 x 11 Thick | Light Bluish Gray | 32525 | 4611705 | €0,33 |
| 2 | Technic Beam 3 x 5 L-Shape Thick | Light Bluish Gray | 32526 | 4211713 | €0,24 |
| 4 | Technic Pin Connector Plate 1 x 2 x 1 2/3 [Two Holes On Top] | Dark Bluish Gray | 32530 | 4210763 | €0,13 |
| 2 | Technic Brick 6 x 8 with 4 x 6 Opening | Black | 32532 | 6448394 | €1,16 |
| 12 | Large Figure Weapon, Claw Hook with Axle | Light Bluish Gray | 32551 | 4234608 | — |
| 2 | Brick Arch 1 x 6 x 2 - Thick Top with Reinforced Underside | Black | 3307 | 330726 | — |
| 2 | Plate 1 x 8 | Dark Bluish Gray | 3460 | 4210998 | €0,18 |
| 4 | Brick 1 x 3 | Light Bluish Gray | 3622 | 4211428 | €0,15 |
| 4 | Plate 1 x 3 | Red | 3623 | 362321 | €0,07 |
| 1 | Slope Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] | Dark Bluish Gray | 3660 | 4211000 | €0,15 |
| 2 | Slope Inverted 45° 2 x 1 | Dark Bluish Gray | 3665 | 4211096 | €0,11 |
| 1 | Slope 75° 2 x 2 x 3 [Hollow Studs] | Black | 3684 | 368426 | — |
| 8 | Technic Brick 1 x 2 [1 Pin Hole] | Light Bluish Gray | 3700 | 4211440 | €0,12 |
| 2 | Technic Brick 1 x 4 [3 Pin Holes] | Dark Bluish Gray | 3701 | 4213607 | €0,17 |
| 5 | Technic Axle 4 | Black | 3705 | 370526 | €0,08 |
| 1 | Technic Axle 6 | Black | 3706 | 370626 | €0,12 |
| 8 | Technic Plate 2 x 4 [3 Holes] | Dark Bluish Gray | 3709 | 4227398 | €0,13 |
| 6 | Technic Plate 2 x 4 [3 Holes] | Black | 3709 | 370926 | €0,13 |
| 2 | Plate 1 x 4 | Black | 3710 | 371026 | €0,12 |
| 1 | Plate 1 x 4 | White | 3710 | 371001 | €0,12 |
| 10 | Technic Bush | Red | 3713 | 6271820 | €0,05 |
| 2 | Technic Axle 10 | Black | 3737 | 373726 | €0,25 |
| 2 | Technic Plate 2 x 8 [7 Holes] | Black | 3738 | 373826 | €0,29 |
| 4 | Technic Axle Pin without Friction Ridges Lengthwise | Tan | 3749 | 4666579 | €0,06 |
| 1 | Plate 2 x 6 | Dark Bluish Gray | 3795 | 4211002 | €0,19 |
| 1 | Plate 2 x 6 | Light Bluish Gray | 3795 | 4211452 | €0,19 |
| 2 | Plate 2 x 10 | Light Bluish Gray | 3832 | 4211462 | €0,29 |
| 2 | Plate Special 1 x 2 with Handles [Flat Ends / Low Attachment] | Black | 3839b | 383926 | €0,11 |
| 2 | Technic Brick 1 x 6 [5 Pin Holes] | Black | 3894 | 389426 | €0,29 |
| 2 | Brick Round 2 x 2 with Axle Hole | Yellow | 3941 | 614324 | €0,11 |
| 2 | Antenna 1 x 4 with Rounded Top | Black | 3957a | 395723 | — |
| 1 | Plate 6 x 6 | Dark Bluish Gray | 3958 | 4211134 | €0,53 |
| 1 | Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) | Red | 4032a | 403221 | €0,06 |
| 2 | Brick Special 1 x 1 with Headlight | Red | 4070 | 407021 | €0,07 |
| 1 | Wedge Curved 6 x 2 Right, Inner Ridges | White | 41747 | 4160101 | — |
| 1 | Wedge Curved 6 x 2 Left, Inner Ridges | White | 41748 | 4160124 | €0,36 |
| 4 | Technic Axle and Pin Connector Perpendicular 3L with 2 Pin Holes | Dark Bluish Gray | 42003 | 6273715 | €0,12 |
| 2 | Technic Pin 1/2 | Light Bluish Gray | 4274 | 4211483 | €0,05 |
| 9 | Technic Axle Pin with Friction Ridges Lengthwise | Black | 43093 | 4206482 | €0,06 |
| 2 | Technic Rotation Joint Disk with Pin Hole and 3L Beam Thick | Dark Bluish Gray | 44224 | 4182751 | €0,47 |
| 2 | Technic Rotation Joint Disk with Pin and 3L Beam Thick | Light Bluish Gray | 44225 | 6332151 | €0,62 |
| 2 | Slope 45° 2 x 8 | Black | 4445 | 4163334 | €0,47 |
| 4 | Hinge Plate 1 x 4 Locking Dual 1 Finger | Light Bluish Gray | 44568 | 6276045 | €0,21 |
| 4 | Hinge Panel 2 x 4 x 3 1/3 Locking Dual 2 Fingers | Black | 44572 | 4193086 | — |
| 2 | Plate 1 x 10 | Black | 4477 | 447726 | €0,16 |
| 4 | Technic Axle 3 | Light Bluish Gray | 4519 | 4211815 | €0,05 |
| 1 | Tool Hammer / Mallet Large | Black | 4522 | 452226 | €0,10 |
| 6 | Wedge Curved 16 x 4 Triple | Black | 45301 | 4200486 | — |
| 6 | Brick Round 1 x 1 with Fins, Open Stud | Dark Bluish Gray | 4588 | 4212352 | — |
| 6 | Cone 1 x 1 [No Top Groove] | Trans-Neon Green | 4589 | 458949 | — |
| 1 | Plate Special 1 x 4 Offset with Bar Holes | Dark Bluish Gray | 4590 | 6302647 | €0,23 |
| 4 | Tap 1 x 1 with Hole in Spout | Light Bluish Gray | 4599a | 459928 | — |
| 4 | Technic Rotation Joint Ball Loop with Two Perpendicular Pins with Friction | Black | 47455 | 4213374 | €0,33 |
| 6 | Wedge Curved 4 x 4 No Top Studs | Yellow | 47753 | 4294741 | — |
| 2 | Technic Brick Special 2 x 2 with Pin Hole, Rotation Joint Socket | Dark Bluish Gray | 48169 | 6278974 | €1,19 |
| 4 | Technic Brick Special 2 x 2 with Pin Hole, Rotation Joint Ball Half [Vertical Side] | Dark Bluish Gray | 48171 | 6492115 | €0,71 |
| 1 | Technic Brick Special 2 x 2 with Pin Hole, with 2 Rotation Joint Sockets | Black | 48172 | 6296186 | €0,96 |
| 1 | Plate Special 1 x 2 [Side Handle Closed Ends] | Black | 48336 | 4225201 | €0,07 |
| 1 | Crane Section 4 x 12 x 3 with 8 Pin Holes | Black | 52041 | 4513143 | — |
| 10 | Animal Body Part, Barb / Claw / Tooth / Talon / Horn, Small | Red | 53451 | 6270107 | €0,07 |
| 1 | Technic Axle and Pin Connector, Perpendicular with Extension | Pearl Light Gray | 53586 | 4286268 | — |
| 6 | Arm Mechanical with Clip [Thin Support] | Pearl Light Gray | 53989 | 4288114 | — |
| 2 | Technic Axle 8 with Stop | Black | 55013 | 4288089 | — |
| 3 | Projectile, Technic Competition Arrow, Liftarm Shaft with Hollow Black Rubber End | Red | 57028c01 | 4504409 | — |
| 2 | Large Figure Weapon Claw Blade, Small | Red | 57528 | 4513223 | — |
| 2 | Launcher, Technic Competition Cannon Flat Bottom [Complete Assembly] | Dark Bluish Gray | 57796 | 4499435 | — |
| 1 | Technic Brick Special 2 x 2 with 10.2mm Balls [Center Mold Indention] | Dark Bluish Gray | 57908 | 4498096 | — |
| 2 | Technic Brick Modified 2 x 2 with Solid Ball and Axle Hole | Dark Bluish Gray | 57909a | — | — |
| 2 | Technic Axle 5.5 with Stop [Rounded Short End] | Dark Bluish Gray | 59426 | 4508553 | €0,11 |
| 2 | Plate Special 1 x 1 with Clip Horizontal [Thick U Clip] | Light Bluish Gray | 6019 | 4211518 | — |
| 1 | Sticker Sheet for Set 7721-1 | Unknown | 60491 | 4512827 | — |
| 1 | Windscreen 5 x 2 x 1 2/3 | Trans-Brown | 6070 | 4204624 | — |
| 1 | Windscreen 5 x 2 x 1 2/3 | Black | 6070 | 4215982 | — |
| 2 | Wave / Flame Rounded with Base Pegs | Trans-Neon Green | 6126a | 4106819 | — |
| 2 | Plate Round 1 x 1 with Solid Stud | Trans-Red | 6141 | 6208450 | €0,04 |
| 4 | Technic Brick Special 2 x 2 with Ball Socket Reinforced and Axle Hole | Dark Bluish Gray | 62712 | 4497254 | — |
| 3 | Technic Axle and Pin Connector Perpendicular | Black | 6536 | 6261371 | €0,10 |
| 2 | Technic Axle Connector Ridged [with x Hole x Orientation] | Red | 6538b | 4125189 | — |
| 46 | Technic Pin Long with Friction Ridges Lengthwise, 2 Center Slots | Black | 6558 | 655826 | — |
| 8 | Technic Axle 3 with Stud | Dark Bluish Gray | 6587 | 4211086 | — |
| 1 | Tile 1 x 6 with Groove | Red | 6636 | 4113858 | €0,13 |
| 2 | Hose, Ribbed 7mm D. 11L / 8.8cm | Pearl Light Gray | 78c11 | 4141672 | — |

## Notes

- Track which of these parts you own and see what is missing: https://www.brickmissing.com/sets/7721-1-combat-crawler-x2
- Inventory data is based on official LEGO inventories via the Rebrickable catalog, updated daily.
- Part images, minifigure lists and related sets are on the set page: https://www.brickmissing.com/sets/7721-1-combat-crawler-x2