Successful Accident

Tap target creature and put a +1/+1 counter on it if {g} was spent to cast Successful Accident. Tap target creature and put a -1/-1 counter on it if {u} was spent to cast Successful Accident. (Do both if {g}{u} was spent.)
"One of the scientists accidentally exposed himself to the experimental bioaugmentation, but it actually worked! He didn't reject it! But the new limbs were rather unexpected..." - Journal of Momir Vig, Simic Visionary