Sea Serpent

Retiring soon

Set number

40912-1

Theme

LEGO Ideas and CUUSOO

Year

2026

Pieces

241

Minifigures

2 total (2 distinct designs) · 2 exclusive

Age

18+

Availability

LEGO Gift with Purchase

Packaging

Box

Box size (L × W × H)

8.1 × 7.5 × 2.4 in (20.5 × 19.1 × 6.1 cm)

Model size (L × W × H)

6.2 × ? × 8.0 in (15.7 × ? × 20.4 cm)

Box weight

0.70 lb (0.319 kg)

Retail price

not yet known

Store prices the store's own offer

Out of stock

• Other sellers on Walmart: $37.88 · shipped by Walmart

Last checked 2026-10-17 05:00:06 UTC

View on Walmart

Current market value

: Avg. New $51.88

• New median $49.99 · typical $44.99–$57.99 · 182 listings

asking prices · updated 2026-10-14 09:26:40 UTC

(US)

	New	Used
Avg. sold price last 6 months	$40.90 725 sold · $27.99–$56.32	$28.00 1 sold · $28.00–$28.00
Avg. asking price for sale now	$48.46 293 for sale · from $36.99	—

Release date

2026-07-07

Retiring

2026-12-31

Shelf life

6 months

Instructions

Instructions

All 7 instruction PDFs

Minifigures (2)

• 

  Griffin Knight, Female, Dark Blue Arms

  fig-017958

  Only in this set
• 

  Griffin Knight, Male, Dark Blue Arms

  fig-017959

  Only in this set

Qty	Image	Part	Name	Color	Sets
1		92950	Brick Arch 1 x 6 Raised Arch	Black	In 98 sets
2		78666	Brick Curved 2 x 1 with Inverted Cutout	Black	In 69 sets
2		93273	Brick Curved 4 x 1 Double, No Studs	Black	In 380 sets
2		3062b	Brick Round 1 x 1 Open Stud	Black	In 789 sets
2		77180	Brick Round, Curved 10 x 2 x 2 with Rounded End Left	Black	In 7 sets
2		77182	Brick Round, Curved 10 x 2 x 2 with Rounded End Right	Black	In 7 sets
1		3039	Brick Sloped 45° 2 x 2	Black	In 684 sets
6		32952	Brick Special 1 x 1 x 1 2/3 with Studs on 1 Side	Black	In 184 sets
2		30136	Brick Special 1 x 2 Palisade [aka Log]	Black	In 241 sets
2		67329	Brick Special 1 x 2 x 1 2/3 with 8 Studs on 3 Sides	Black	In 101 sets
1		3937	Hinge Brick 1 x 2 Base	Black	In 639 sets
1		6134	Hinge Brick 2 x 2 Top Plate Thin	Black	In 571 sets
4		1927	Hinge Plate 1 x 4 Swivel Top / Base - Hollow Clip [Complete Assembly]	Black	In 99 sets
5		3023	Plate 1 x 2	Black	In 2,911 sets
3		3710	Plate 1 x 4	Black	In 2,176 sets
2		3021	Plate 2 x 3	Black	In 1,906 sets
13		35480	Plate Special 1 x 2 Rounded with 2 Open Studs	Black	In 579 sets
1		48336	Plate Special 1 x 2 [Side Handle Closed Ends]	Black	In 731 sets
1		60470b	Plate Special 1 x 2 with Clips Horizontal [Open O Clips]	Black	In 591 sets
1		71752	Plate Special 2 x 2 x 2/3 with Axle Hole and Grill on Sides (Haybale)	Black	In 153 sets
1		3737	Technic Axle 10	Black	In 689 sets
1		32123b	Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced	Black	In 15 sets
1		49153	Tile Special 2 x 2 with Top Pin [Squared Holes]	Black	In 65 sets
1		15535	Tile Special Round 2 x 2 with Hole	Black	In 194 sets
2		64567	Weapon Lightsaber Hilt with Bottom Ring	Black	In 344 sets
1		51739	Wedge Plate 2 x 4	Black	In 214 sets
8		3386	Plate Special 1 x 1 x 2/3 Half Round with Side Stud	Blue	In 18 sets
4		43093	Technic Axle Pin with Friction Ridges Lengthwise	Blue	In 2,438 sets
2		3069b	Tile 1 x 2 with Groove	Blue	In 457 sets
2		4162	Tile 1 x 8 with Groove	Blue	In 133 sets
10		14719	Tile 2 x 2 Corner	Blue	In 30 sets
1		43723	Wedge Plate 3 x 2 Left	Blue	In 73 sets
1		43722	Wedge Plate 3 x 2 Right	Blue	In 73 sets
1		4495b	Flag 4 x 1 Wavy [First Wave Right]	Dark Blue	In 21 sets
6		32952	Brick Special 1 x 1 x 1 2/3 with Studs on 1 Side	Dark Bluish Gray	In 190 sets
1		87580	Plate Special 2 x 2 with Groove and Center Stud (Jumper)	Dark Bluish Gray	In 489 sets
1		89678	Technic Pin 1/2 with Friction	Dark Bluish Gray	In 408 sets
1		3069b	Tile 1 x 2 with Groove	Dark Bluish Gray	In 744 sets
1		2489	Barrel 2 x 2 x 2	Dark Brown	In 113 sets
6		5404	Brick Sloped 18° 2 x 1 x 2/3	Dark Brown	In 14 sets
1		4032a	Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening)	Dark Brown	In 100 sets
2		4972pr0005	Shield Triangular with Spiked Top with Red/Blue Griffin on Yellow Background Print	Flat Silver	Exclusive
1		53454	Weapon Axe Head, Clip-on (Viking) [Thick Clip]	Flat Silver	In 78 sets
1		93789	Weapon Pike / Spear Flat End	Flat Silver	In 95 sets
1		18034	Weapon Sword with Thick Crossguard (Roman Gladius)	Flat Silver	In 41 sets
6		3386	Plate Special 1 x 1 x 2/3 Half Round with Side Stud	Light Bluish Gray	In 179 sets
6		4304	Plate Special 2 x 2 x 2/3 with Two Studs On Side and Two Raised [Half Hollow Anti-stud] - Updated Version	Light Bluish Gray	In 168 sets
1		26603	Tile 2 x 3	Light Bluish Gray	In 265 sets
2		2821	Container Box 2 x 2 x 1 Reinforced Bottom	Medium Nougat	In 66 sets
1		98138pr0018	Tile Round 1 x 1 with Cookie Print	Medium Nougat	In 188 sets
1		2343	Equipment Goblet / Glass	Pearl Gold	In 224 sets
2		4495b	Flag 4 x 1 Wavy [First Wave Right]	Pearl Gold	In 79 sets
8		6141	Plate Round 1 x 1 with Solid Stud	Pearl Gold	In 680 sets
1		98138pr0283	Tile Round 1 x 1 with Golden Crown Print	Pearl Gold	In 39 sets
2		99563	Tile Special 1 x 2 with Sloped Walls AKA Money / Gold Bar [Ingot]	Pearl Gold	In 255 sets
3		38320	Window Pane Latticed 1 x 2 x 2	Pearl Gold	In 67 sets
4		5907	Brick Curved 1 x 2 x 1 2/3 with 1 Cutout	Red	In 10 sets
1		4282	Plate 2 x 16	Red	In 61 sets
4		3957b	Antenna 1 x 4 with Flat Top	Reddish Brown	In 142 sets
4		3484	Bar 1L with Clip [Cut Edges and One Side Hole] [Full Clip]	Reddish Brown	In 88 sets
6		36840	Bracket 1 x 1 - 1 x 1 Inverted	Reddish Brown	In 127 sets
2		79389	Bracket 1 x 1 - 1 x 2	Reddish Brown	In 47 sets
10		73825	Bracket 1 x 1 - 1 x 2 Inverted	Reddish Brown	In 82 sets
2		99780	Bracket 1 x 2 - 1 x 2 Inverted	Reddish Brown	In 170 sets
2		59900	Cone 1 x 1 [Top Groove]	Reddish Brown	In 323 sets
2		87585	Equipment Oar / Paddle [Reinforced]	Reddish Brown	In 97 sets
2		24122	Large Figure Weapon Lightsaber Hilt with Axle Hole and Two Bar Holders	Reddish Brown	In 47 sets
2		3710	Plate 1 x 4	Reddish Brown	In 828 sets
4		3021	Plate 2 x 3	Reddish Brown	In 616 sets
2		3020	Plate 2 x 4	Reddish Brown	In 907 sets
1		3795	Plate 2 x 6	Reddish Brown	In 556 sets
1		3032	Plate 4 x 6	Reddish Brown	In 248 sets
1		88072	Plate Special 1 x 2 with Bar Up [Horizontal Arm 5mm]	Reddish Brown	In 97 sets
2		87580	Plate Special 2 x 2 with Groove and Center Stud (Jumper)	Reddish Brown	In 272 sets
2		59443	Technic Axle Connector Smooth [with x Hole + Orientation]	Reddish Brown	In 222 sets
3		62462	Technic Pin Connector Round [Slotted]	Reddish Brown	In 138 sets
1		87079	Tile 2 x 4 with Groove	Reddish Brown	In 267 sets
1		98138	Tile Round 1 x 1	Reddish Brown	In 133 sets
2		25269	Tile Round 1 x 1 Quarter	Reddish Brown	In 194 sets
2		24299	Wedge Plate 2 x 2 Left	Reddish Brown	In 28 sets
2		24307	Wedge Plate 2 x 2 Right	Reddish Brown	In 25 sets
2		41770	Wedge Plate 4 x 2 Left	Reddish Brown	In 107 sets
2		41769	Wedge Plate 4 x 2 Right	Reddish Brown	In 107 sets
2		54384	Wedge Plate 6 x 3 Left	Reddish Brown	In 10 sets
2		54383	Wedge Plate 6 x 3 Right	Reddish Brown	In 11 sets
3		90195	Window 1 x 2 x 2 Castle	Reddish Brown	In 27 sets
2		3666	Plate 1 x 6	Tan	In 527 sets
1		87994	Bar 3L	White	In 173 sets
4		22885	Brick Special 1 x 2 x 1 2/3 with 4 Studs on 1 Side	White	In 262 sets
2		3023	Plate 1 x 2	White	In 2,605 sets
2		3020	Plate 2 x 4	White	In 1,731 sets
1		118832	Sail, 9 x 12 with 4 Holes in White with Red Griffin Print	White	Exclusive
1		32123b	Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced	Black	In 15 sets	extra
1		64567	Weapon Lightsaber Hilt with Bottom Ring	Black	In 344 sets	extra
1		89678	Technic Pin 1/2 with Friction	Dark Bluish Gray	In 408 sets	extra
1		18034	Weapon Sword with Thick Crossguard (Roman Gladius)	Flat Silver	In 41 sets	extra
1		98138pr0018	Tile Round 1 x 1 with Cookie Print	Medium Nougat	In 188 sets	extra
1		6141	Plate Round 1 x 1 with Solid Stud	Pearl Gold	In 680 sets	extra
1		98138pr0283	Tile Round 1 x 1 with Golden Crown Print	Pearl Gold	In 39 sets	extra
1		38320	Window Pane Latticed 1 x 2 x 2	Pearl Gold	In 67 sets	extra
1		98138	Tile Round 1 x 1	Reddish Brown	In 133 sets	extra
1		25269	Tile Round 1 x 1 Quarter	Reddish Brown	In 194 sets	extra
1		87994	Bar 3L	White	In 173 sets	extra

Building instructions

• 40912_DE_BI_Info_Booklet extra
• 40912_ES_BI_Info_Booklet extra
• 40912_FR_BI_Info_Booklet extra
• 40912_IT_BI_Info_Booklet extra
• 40912_ZHSI_BI_Info_Booklet extra
• BI 3101, 80+4, 40912 V29
• BI 3101, 80+4, 40912 V39

PDFs from LEGO.com. The same booklet is often printed in several versions (e.g. V29 EU A4 format, V39 US Letter format).