Mountortoise

Mountortoise comes into play tapped, with 9 time counters on it.
Remove a time counter from Mountortoise at the beginning of your upkeep. If Mountortoise has no time counters on it, it is a 10/10 Turtle creature with Trample that is still a land.
{t}: Add {r} or {g} to your mana pool, and Mountortoise deals 1 damage to you.