Bowser's Castle Boss Battle

Notable parts

• 5 printed parts are only in this set: Brick 1 x 2 with Black and Yellow Eyes (Dry Bones) Print (White); Plate Round Corners 4 x 4 x 2/3 Circle with Reduced Knobs and Two Arrows and… (Black); Tile 2 x 2 with Bowser and Barcode Print (Sticker) (Green); Tile 2 x 2 with Dry Bones, Pupils and Barcode Print (Sticker) (Dark Bluish Gray); Tile Round Corners 4 x 4 x 2/3 with Two Circle Arrows and Barcode Print… (Medium Nougat).
• 17 parts appear in only a few other sets: Tile Special 2 x 3 with 2 Clips [Thick Open O Clips] with Bowser Head Print (Black) ×2 — also in 71360 Adventures with Mario (all Super Mario); Brick 1 x 3 with Open Mouth Smile with Teeth and Tongue (Boo) Print (White) — also in 71399 Luigi's Mansion Entryway (all Super Mario); Brick Curved 1 x 2 x 1 No Studs with Jagged Black Line (Dry Bones Mouth) Print (White) — also in 71436 King Boo's Haunted Mansion (all Super Mario); Brick Curved 1 x 2 x 1 No Studs with Two Black Tear Drops (Dry Bones Nostrils)… (White) — also in 71436 King Boo's Haunted Mansion (all Super Mario); Tile 2 x 2 with Clock in Straight Border and Barcode Print (Sticker) (Dark Turquoise) — also in 71365 Piranha Plant Power Slide (all Super Mario); Tile Round 2 x 2 with Bottom Stud Holder with Three Dark Brown Lines Print (Tan) — also in 71436 King Boo's Haunted Mansion (all Super Mario); Arm, Long, with Technic Pin (Light Aqua) ×2 — also in 71436 King Boo's Haunted Mansion, 42643 Cotton Candy Stand and Scooter; Brick 1 x 3 with Black Eyes and Eyebrows (Boo) Print (White) — also in 71399 Luigi's Mansion Entryway, 71440 Adventures with Interactive LEGO Luigi (all Super Mario); Brick 2 x 2 with Clock Timer on Two Sides Print (Dark Turquoise) — also in 71365 Piranha Plant Power Slide, 71389 Lakitu Sky World (all Super Mario); Brick Wedged, Sloped 4 x 4 with White Underside Pattern (Koopa Troopa Shell) (Dark Bluish Gray) — also in 71394-9, 71436 King Boo's Haunted Mansion (all Super Mario); Feet, 2 x 2 x 2/3 with 4 Studs on Top (Light Aqua) — also in 71413-3, 71436 King Boo's Haunted Mansion (all Super Mario); Tile 2 x 2 with Boo and Barcode Print (Sticker) (White) — also in 71399 Luigi's Mansion Entryway, 71440 Adventures with Interactive LEGO Luigi (all Super Mario); and 5 more.
• 3 parts are otherwise only found in Super Mario sets: Plate Round Corners 8 x 8 x 2/3 Circle with Reduced Knobs (Red) ×2; Plate Round Corners 4 x 4 x 2/3 Circle with Reduced Knobs (Medium Nougat); Plate Special 8 x 8 x 2/3 Octagon with Rim (White).
• 12 moulds first came out in 2020, including in this set: Plate Round Corners 4 x 4 x 2/3 Circle with Reduced Knobs ×9; Plate Round Corners 6 x 6 x 2/3 Circle with Reduced Knobs ×8; Plate Round Corner 3 x 3 with 2 x 2 Round Cutout ×4; Arm, Long, with Technic Pin ×2; Brick Special 1 x 2 x 1 2/3 with 8 Studs on 3 Sides ×2; and 7 more.
• 12 existing moulds first came out in their colour in 2020, including in this set: Brick Wedged, Sloped 45° 2 x 2 Corner (Green) ×12; Plate 2 x 14 (Red) ×6; Animal Body Part, Barb / Claw / Tooth / Talon / Horn, Medium (Tan) ×2; Brick Arch 1 x 4 (Bright Light Orange) ×2; Brick Curved 1 x 2 x 1 No Studs (Dark Bluish Gray) ×2; and 7 more.

Calculated from Rebrickable’s public set inventories, excluding sticker sheets and spare parts.