How many pieces does the LEGO Cat Birthday Party & Tree House (42666-1) have?

The LEGO Cat Birthday Party & Tree House set (42666-1) contains 321 pieces. It was released in 2025 as part of the LEGO Friends theme.

How can I find missing parts for LEGO set 42666-1?

On BrickMissing you can check which parts from the LEGO Cat Birthday Party & Tree House (42666-1) you already own. Add your LEGO collection and we'll show exactly which of the 321 pieces you're missing and which you already have.

Can I build the LEGO Cat Birthday Party & Tree House with parts I already have?

Use BrickMissing's free parts checker to find out. Add LEGO sets you own to your collection and we'll cross-reference all 321 parts to show your buildability percentage and which specific pieces you still need.

What theme is the LEGO Cat Birthday Party & Tree House from?

The LEGO Cat Birthday Party & Tree House (42666-1) belongs to the LEGO Friends theme. You can browse all Friends sets on BrickMissing to find more sets from this theme.

Cat Birthday Party & Tree House - View 9

Cat Birthday Party & Tree House

🏷️ 42666-1•🎨 Friends•📅 2025•🧱 321 parts•Intermediate

The LEGO Friends 42666 Cat Birthday Party & Tree House invites you to a festive celebration in Heartlake City. This 321-piece set brings LEGO Friends characters Leo and Paisley together with Churro, the birthday cat, and four additional feline friends for a grand event. Explore the multi-level cat tree house, complete with a fish-shaped piñata, a refreshing water fountain, cat grass, and a hidden litter box. Adorned with colorful birthday banners, presents, and cheerful cat-shaped balloons, the scene culminates around a rotating table where Churro’s special birthday cake awaits. This vibrant model offers many detailed components, from the intricate piñata design to the functional rotating dining area, ensuring a lively display.

Parts Inventory

🧱 321 parts

Part	Color	Qty
Sticker Sheet for Set 42666-1 10113040	Unknown	1×
Bar Holder with Clip 11090	White	2×
Plate Special 1 x 2 with Clip Horizontal on Side 11476	White	1×
Slope Curved 2 x 1 No Studs [1/2 Bow] 11477	Bright Green	2×
Animal, Cat, Sitting with Dark Brown Stripes, White Chest, Ears print 11602pr0010	Medium Brown	1×
Headwear Accessory Bow with Heart, Long Ribbon and Pin 11618	Lavender	1×
String with End Studs 11L Overall 14226c11	Black	1×
Brick Arch 1 x 5 x 4 [Continuous Bow, Raised Underside Cross Supports] 14395	Tan	2×
Brick Arch 1 x 6 x 2 - Thin Top without Reinforced Underside [New Version] 15254	Medium Azure	1×
Brick Round 2 x 2 Dome Bottom [Open Stud] 15395	Bright Pink	2×

Showing 10 of 146 parts

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Headwear Accessory Bow with Heart, Long Ribbon and Pin	11618	Lavender	1×
String with End Studs 11L Overall	14226c11	Black	1×
Brick Arch 1 x 5 x 4 [Continuous Bow, Raised Underside Cross Supports]	14395	Tan	2×
Brick Arch 1 x 6 x 2 - Thin Top without Reinforced Underside [New Version]	15254	Medium Azure	1×
Brick Round 2 x 2 Dome Bottom [Open Stud]	15395	Bright Pink	2×
Plate Round 1 x 2 Half Circle with Stud (Jumper)	1745	Black	1×
Tile Round 1 x 2 Half Circle	1748	Medium Azure	2×
Brick Arch 1 x 3 x 2 Inverted [Inside Bow]	18653	Medium Azure	2×
Plate Special Round 2 x 2 with Center Stud (Jumper Plate)	18674	Dark Pink	4×
Plate Special Round 2 x 2 with Center Stud (Jumper Plate)	18674	Black	2×
Plate Special Round 2 x 2 with Center Stud (Jumper Plate)	18674	Bright Green	3×
Plant, Flower with 5 Pointed Petals and Pin	18853	Light Aqua	1×
Brick Special 1 x 2 x 1 2/3 with 4 Studs on 1 Side	22885	Red	1×
Bar Holder with Hole and Bar Handle	23443	Reddish Brown	1×
Large Figure Weapon Lightsaber Hilt with Axle Hole and Two Bar Holders	24122	Reddish Brown	2×
Headwear Accessory Hat with Small Pin, Clown / Party with Pin	24131	Pearl Gold	1×
Plant, Leaves 4 x 3	2423	Lime	8×
Tile 1 x 4 with Groove	2431	Bright Green	2×
Plant, Flower, Plate Round 1 x 1 with 5 Petals	24866	Lavender	2×
Plant, Flower, Plate Round 1 x 1 with 5 Petals	24866	Bright Green	4×
Plant, Flower, Plate Round 1 x 1 with 5 Petals	24866	Bright Light Yellow	2×
Brick Round 1 x 1 diameter Tube with 90 Degree Elbow (2 x 2 x 1) and Axle Holes (Crossholes) at each end	25214	Tan	6×
Animal, Cat, Chubby with orange Face, Toes, Medium Blue/Lime Eyes print	2652pr0003	White	1×
Animal, Cat, Chubby with Bright Green Eyes, Light Bluish Grey Fur print	2652pr0007	Dark Bluish Gray	1×
Tile 2 x 3	26603	Black	2×
Turntable 2 x 2 Female	27448	White	1×
Tile 2 x 2 Curved, Macaroni	27925	Coral	2×
Container Box 2 x 2 x 1 Reinforced Bottom	2821	Bright Light Orange	1×
Container Box 2 x 2 x 1 Reinforced Bottom	2821	Bright Pink	3×
Brick Special 1 x 2 with Grille	2877	Tan	3×
Brick 2 x 3	3002	Dark Orange	1×
Brick 1 x 2	3004	Bright Light Orange	3×
Brick 1 x 2	3004	Coral	3×
Brick 1 x 2	3004	Dark Orange	3×
Brick 1 x 1	3005	Medium Azure	5×
Brick 1 x 1	3005	Coral	3×
Brick 1 x 1	3005	Bright Light Orange	3×
Brick 1 x 4	3010	Medium Azure	2×
Plate 2 x 4	3020	Medium Lavender	1×
Plate 2 x 4	3020	Orange	2×
Plate 2 x 3	3021	Light Aqua	1×
Plate 2 x 2	3022	Light Bluish Gray	1×
Plate 1 x 2	3023	Dark Orange	5×
Plate 6 x 10	3033	Lime	2×
Bar 4L (Lightsaber Blade / Wand)	30374	White	2×
Tile 2 x 2 with Groove	3068b	Bright Light Orange	1×
Tile 2 x 2 with Groove	3068b	Bright Pink	2×
Tile 1 x 2 with Groove	3069b	Medium Azure	4×
Tile 1 x 2 with Groove	3069b	Red	2×
Tile 1 x 2 with Cat Food Box, Cat, White 'MEOW BITS' print	3069bpr9932	Light Aqua	2×
Plate Special 1 x 2 with Door Rail	32028	Tan	3×
Technic Axle 2 Notched	32062	Red	6×
Plant, Plate 1 x 1 Round with 3 Leaves	32607	Yellowish Green	25×
Plant, Plate 1 x 1 Round with 3 Leaves	32607	Bright Green	4×
Slope Curved 2 x 2 x 2/3 Inverted	32803	Bright Light Blue	2×
Plate Round 1 x 1 with Hollow Stud and Horizontal Bar 1L	32828	Black	1×
Slope 33° 3 x 2	3298	Reddish Brown	1×
Headwear Accessory Crown / Tiara	33322	Pearl Gold	1×
Bar 1L with Clip [Cut Edges and One Side Hole] [Full Clip]	3484	Reddish Brown	2×
Plate Special 4 x 4 with 3 x 3 Quarter Round Cutout	35044	Bright Pink	1×
Plate Special 4 x 4 with 3 x 3 Quarter Round Cutout	35044	Yellow	1×
Plate Special 1 x 2 Rounded with 2 Open Studs	35480	Tan	1×
Plate Special 1 x 2 Rounded with 2 Open Studs	35480	Bright Green	2×
Brick 1 x 3	3622	White	2×
Brick Arch 1 x 4	3659	Bright Light Orange	1×
Technic Brick 1 x 2 [1 Pin Hole]	3700	Reddish Brown	1×
Plate 1 x 4	3710	Bright Green	2×
Brick Curved 1 x 2 x 1 No Studs	37352	Tan	2×
Plant, Stem with 3 Leaves and Bottom Pin	37695	Bright Green	6×
Equipment Candlestick	37762	Reddish Brown	6×
Equipment Candlestick	37762	Black	1×
Wave / Flame Small with Pin	37775	Trans-Orange	1×
Equipment Shovel [Rounded Handle End]	3837	Flat Silver	1×
Antenna 1 x 4 with Flat Top	3957b	Dark Orange	1×
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening)	4032a	Bright Pink	3×
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening)	4032a	Medium Azure	2×
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening)	4032a	Medium Nougat	1×
Brick Special 1 x 1 with Headlight	4070	Bright Light Blue	2×
Plate 8 x 8 with Rounded End	41948	Magenta	1×
Technic Pin 1/2	4274	Light Bluish Gray	1×
Plate 1 x 10	4477	Medium Azure	3×
Dish 2 x 2 Inverted [Radar]	4740	Black	2×
Dish 2 x 2 Inverted [Radar]	4740	Trans-Light Blue	1×
Brick Special 1 x 1 with Studs on 2 Sides	47905	Black	1×
Plant, Leaves Stacked 4 x 5 x 1 2/3	5058	Bright Green	2×
Plant, Leaves Stacked 4 x 5 x 1 2/3	5058	Lime	3×
Wedge Plate 2 x 4	51739	Black	1×
Plate Round 1 x 1 Swirled Top / Poo	53119	Reddish Brown	1×
Animal Body Part, Barb / Claw / Tooth / Talon / Horn, Small	53451	Bright Green	4×
Slope 30° 1 x 1 x 2/3 (Cheese Slope)	54200	Bright Light Blue	2×
Brick Round 2 x 2 Dome Top with 2 Ears	5690	Bright Pink	2×
Technic Axle Connector Hub with 3 Axles at 120°	57585	Light Bluish Gray	3×
Plant, Flower, Peony Rose with 2 Layers	5904	Medium Lavender	2×
Technic Axle Connector Smooth [with x Hole + Orientation]	59443	Tan	6×
Cone 1 x 1 [Top Groove]	59900	Trans-Light Blue	1×
Cone 1 x 1 [Top Groove]	59900	Tan	6×
Plate Round Corner 6 x 6	6003	Lime	1×
Plate Round Corner 6 x 6	6003	Black	2×
Window 1 x 4 x 3 without Shutter Tabs	60594	White	1×
Plate Round 1 x 1 with Solid Stud	6141	Bright Pink	4×
Plate Round 1 x 1 with Solid Stud	6141	Trans-Light Blue	1×
Brick Arch 1 x 4 x 2	6182	Coral	1×
Cylinder Half 2 x 4 x 4	6259	Tan	3×
Animal, Fish [Hollow Stud Mouth]	64648	Bright Light Blue	1×
Plate Special 2 x 4 with Groove and Two Center Studs (Jumper)	65509	Bright Green	4×
Wool / Yarn	6900	Dark Pink	1×
Wool / Yarn	6900	Bright Light Yellow	1×
Headwear Accessory Hat with Small Pin, Cap	6913	Lime	1×
Animal, Cat, Kitten Sitting with Open Eyes, White Mouth, Nougat Paws print	69902pr0003	Nougat	1×
Animal, Cat, Kitten Sitting with Yellow Eyes, Dark Pink Tongue print	69902pr0004	Black	1×
Plate Special 2 x 2 x 2/3 with Axle Hole and Grill on Sides (Haybale)	71752	Tan	1×
Hose Rigid 3mm D. 9L / 7.2cm	75c09	Black	1×
Plate Special 1 x 2 with Clip Vertical on End	78256	Reddish Brown	1×
Bar 2L with Stop in Center	78258	White	1×
Bar 2L with Stop in Center	78258	Tan	4×
Bar 2L with Stop in Center	78258	Reddish Brown	2×
Brick Curved 2 x 1 with Inverted Cutout	78666	Bright Light Orange	2×
Brick Curved 2 x 1 with Inverted Cutout	78666	Coral	2×
Flag 2 x 2 Square, Flared Clip Edge [Thick Clips]	80326	White	3×
Brick Special 1 x 2 with 1 Center Stud on 1 Side, Bottom Stud Holder	86876	Bright Light Blue	1×
Plate 1 x 1 x 2/3 with Open Stud	86996	Dark Orange	1×
Brick Round 4 x 4 Centre Hole	87081	Yellow	1×
Panel 1 x 2 x 3 [Side Supports / Hollow Studs]	87544	White	2×
Plate Special 2 x 2 with Groove and Center Stud (Jumper)	87580	Bright Pink	1×
Plate Special 2 x 2 with Groove and Center Stud (Jumper)	87580	Medium Azure	5×
Plate Special 2 x 2 with Groove and Center Stud (Jumper)	87580	Yellow	1×
Bar 5L with Handle (Friction Ram)	87618	Black	1×
Plate Special 1 x 2 with Bar Up [Horizontal Arm 5mm]	88072	Tan	4×
Plate Special 1 x 2 with Bar Up [Horizontal Arm 5mm]	88072	Light Bluish Gray	2×
Cupboard 2 x 3 x 2 with Hollow Studs	92410	Black	1×
Tile Round 1 x 1	98138	Trans-Yellow	1×
Tile Round 1 x 1 with Offset Black Eye Print	98138pr0008	White	2×
Tile Round 1 x 1 with Animal Track Print	98138pr0056	Medium Nougat	6×
Minidoll Head Thick Black Eyebrows, Reddish Brown Eyes, Smile print	92198pr0335	Medium Nougat	1×
Minidoll Torso Boy with Medium Nougat Arms and Hands with Magenta/Coral Jacket, Medium Blue Trim, White Shirt, Orange/Azure Shapes print	11408c02pr0013	Medium Nougat	1×
Hair Scruffy and Swept Right	40938	Reddish Brown	1×
Minidoll Hips and Cargo Pants with Nougat Legs, Medium Azure/White Shoes print [Thin Hinge]	2268c01pr0006	Yellow	1×
Hair, Long Wavy Across Face	2645	Dark Red	1×
Minidoll Head Dark Red Eyebrows, Medium Azure Eyes, Nougat Lips print	92198pr0346	Light Nougat	1×
Minidoll Torso Girl with Bright Light Yellow Top, Coral/Dark Blue Shapes, Writing, Lavender Shirt print, Light Nougat Arms and Hands	92456c01pr0035	Light Nougat	1×
Minidoll Hips and Shorts with Warm Tan Legs, Dark Tan Shoes, White Laces, Socks, Laces	36198c01pr0004	Medium Lavender	1×

Build DNA

Parts inventory insights for Cat Birthday Party & Tree House

321 pieces puts this build +5% against the average Friends set and -50% against the average 2025 release.

LEGOFRIENDS

Vs average Friends set

+5%+15 parts

This set321

Average set306

Average Friends set: 306 pieces across 539 other sets.

Vs average 2025 set

-50%-316 parts

This set321

Average set637

Average 2025 set: 637 pieces across 561 other sets.

Color profile

38different colors

Dominant color

Tan

Tan41x

13%

Bright Green35x

11%

Medium Azure26x

Yellowish Green25x

Unique parts

2.8 pieces per unique type

116

Repeat factor

Average pieces per unique type.

Most used part

Plant, Plate 1 x 1 Round with 3 Leaves

29x

Results are based on official LEGO part inventories. Accuracy improves as you confirm set completeness.

This site is not affiliated with or endorsed by the LEGO Group.

Build Insights🧩116unique parts🎨38different colors📊8.4avg. parts per color🏆29×Plant, Plate 1 x 1 Round with 3 Leaves

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