Apologetic Mushroom

Originally from Kuroko No Basuke; a person who blames themselves for everything, and constantly apologises for their existence.

Hannah: *picks up phone* Hello?
Peter: Hannah, I'm sorry I'm such a loser! Please can we get back together! I'm so sorry! Please forgive me I'm so sorry!
Hannah: I wouldn't have broken up with you if you weren't such an apologetic mushroom!
Peter: I'm sorry!