Shoot off both arms on a Hulk and then extract while it's alive.

Defeat a Bile Titan.

Extract with a full squad on a Hard difficulty or more mission.

Complete ''Arkham Barely Believe It''

Get to the Spaghetti save point in Snowdin.

Arrive at Snowdin.

Get two items.

Reach the mouse hole in the Ruins.

Get an A++ on a Story level

Become inedible.

Complete a level without dying

Complete ''It's Good To Be Bad''

Unlock every trophy.