Isaac turns into a walking Mushroom after picking up three distinct items from the following list. Grants a Red Heart container.
Name
ID
Icon
Quote
Description
1up!
11
Extra life
Gives Isaac an extra life. Upon death, he will respawn in the previous room with full health and lose the 1up!.
Blue Cap
342
HP + tears up + shot speed down
Grants 1 Red Heart container and increases tears, but decreases shot speed.
Magic Mushroom
12
All Stats Up!
Increases most stats, enlarges Isaac, grants a heart container and restores all health.
Mini Mush
71
Speed + range up
Increases Speed and Shot Height and decreases Isaac's size, but lowers Range.
Odd Mushroom
121
DMG up
Grants an empty heart container. Increases damage, range and shot height while reducing speed.
Odd Mushroom
120
Fire rate up
+1.7 tears, +0.3 speed, reduces damage.
God's Flesh
398
Shrink shot
Tears now have a random chance to apply a shrinking effect, causing enemies to shrink in size and also run away from Isaac. Shrunk enemies can be crushed and killed by walking over them.
The name Fun Guy is a slang term for psychedelic mushrooms and a wordplay on fungi .
Fun Guy may be a reference to the character of the same name in Chrono Cross.
Fun Guy "s appearance may be a reference to the character Toad , a humanoid mushroom from the Mario franchise.