Boletis, Symbiotic Brute

Trample
At the beginning of your upkeep, you may pay {b}{g}. If you do, return Boletis to the battlefield
under your control, and he gets -4/-2 until your
next upkeep. If he would die before your next
upkeep, exile him instead.
If Boletis would die due to damage from a Black, Green, or Blue source, regenerate Boletis.