Horrific Mutation

Put a +1/+1 counter on target creature. Then roll a six-sided die. That creature gets +X/-X until end of turn, where X is equal to the die roll. If X is 5 or greater, that creature fights another creature chosen at random. (Each deals damage equal to its power to the other.)
"Well... It could've gone worse. Right?"
- Valoth, Mad Biomancer