It's a Bully

It's a Bully is the tertiary antagonist in Baldi's Basics in Education & Learning. He also appeared in Strawberry Getaway.

History
When approached, he will steal a random item from the player's inventory. Afterwards, he will mysteriously vanish and let the player pass. However, if the player approaches It's a Bully with nothing in their inventory, he will continue to block the player's path.

In Strawberry Getaway, It's a Bully is friends with Papyrus.