Unknown Specimen 2 is one of the new specimens encountered in Endless Mode.
He is a brown animatronic otter with a perpetually open mouth.
Otto lacks a chase theme, the only indication of his presence being his deep belly laugh. He enters the room very quickly but slows down to a crawl immediately after. He deals a very small amount of damage on contact.
If the player's health bar is depleted by the specimen, they are met with a jumpscare where his face fills the screen and shakes violently.
- He is based on the animatronic characters from the horror game Five Nights at Freddy's, namely Freddy Fazbear, who has a similar-sounding laugh. He is drawn to look more like fan-art than actual game graphics.
- Due to his low damage and speed, he appears to be a joke character.