Bobby, Mad Scientist

When Bobby or another creature enters the battlefield under your control you may
choose to put up to one counter of
Trample, Flying, or a +1/+1 counters.
{t}, Pay 2 life: Exile Bobby, Mad Scientist and
return it under your control transformed.
Activate this ability only if you control five
or more creatures with any number of
Trample, Flying, or +1/+1 counters.