Ice Slime

{4}{w/u}: Oozify 3 (Choose target creature you control. If it is a Slime, put 3 +1/+0 counters on it if it has greater toughness than power. If it is not a Slime, it becomes a slime in addition to its other creature types)
You can pay this creature's Oozify cost by tapping slimes you control for {1} each.
Convoke