DC has a few:
Rash
Reverse Rash
Kid Rash
Metamorpoo
Harley Quim (ok, not poo, but still funny!)
Pooson Ivy
Ra's Al Poo or Ra's Anal Ghul
Poo-Face
Poo Beetle
Pooster Gold
Dr. Poolaris
Pooalax or Analax
Beppoo the Super Monkey
Brother Pooer the Geek
Pooer Girl
Zatanal
I think the Pooson Ivy/Harley Quim would be a great villainess teamup.