Boxy Boo And Kissy Missy by Antiania on DeviantArt

Boxy Boo, Poppy Playtime Wiki

Boxy Boo, Villains Wiki

It's not a new character attacking Bron, those are Boxy Boo's padded claws. You can even hear their crank turning 3 times before and their jump scare sound as they attack Bron.

Boxy Boo by DJTundraIce -- Fur Affinity [dot] net

Fat Boxy Boo! by VLCVideo -- Fur Affinity [dot] net

Huggy Wuggy Bullying Boxy Boo by Antiania on DeviantArt

Boxy Boo - Box Surprise Boo Concept Skin (I made a concept for Boxy Boo based on the surprise boxes that a toy includes) : r/ProjectPlaytime

Boxy Boo, GameToons Wiki

Figure Poppy Play Time Boxy Boo Robot Huggy - Denmark

40cm Project Boxy Boo Plush Toy,devil Within The Box Plush Boxy Boo Plush Toys Gift For Boy Girl Or Horror Game Fans