Changed in NT:TE
You may be looking for the modded character instead
Yung Cuz, or Y.C. for short is the unfinished sixteenth Vanilla Mutant. He has a voice, sprites, and menu text, but has no abilities as he was unfinished.
Y.C. was adapted into a C Skin for Y.V. in Nuclear Throne Together, and a standalone mod has been created with an attempt to finish the character.
The text found for Y.C.'s abilities is "LIL BUDDY" and "GOT UR BACK." It's unclear what these could have meant and it's likely we will never know.
Possible speculation includes him having a friendly helper, being able to call for help in some way, or being a support character meant for co-op.
Y.C.'s Throne Butt has no effect. The text for it is "GO 4 IT" which similarly has no known meaning.
While not a true ability, this is being listed for completion. If you press B on the keyboard while playing Y.C., an airhorn sound will play and the screen will shake. This can also be done when loading into levels and picking Mutations.
Game God has no effect but has completed artwork. The text for it is "PLAY HARD."
Car God has no effect but has completed artwork. The text for it is "FAST LYFE."