Q: Is the Two-Face Creeper supposed to give you an advantage when using the Two-Face Flip promo card?

The Two-Face Flip promo card says that if you have the Two-Face Creeper, you get to take the best two out of three coin flips, instead of just one coin flip. Mathematically, however, those both give you the same 50/50 chance of a win.

A: Yes, having the Two-Face Creeper is intended to give you an advantage in the coin flip.

You get to flip the coin, and if you win on the first flip, great! You don’t have to keep flipping and risk two failures.
If you lose the first coin flip, however, you get to claim best two out of three, getting an extra chance to win by getting the next two coin flips correct.