Ghalta, Primal Hunger
Ghalta, Primal Hunger is great example of a stomper commander in mono green. Massive creature with trample, and often it is cast with only two green mana! Ghalta decks are balancing between voltron and stomper decks, as commander damage wincon is trivial to achieve.
Themes for Ghalta, Primal Hunger
Stompers
As green has the best mana ramp options in the format, and the biggest creatures, too, it is only natural that big creatures / stompers decks are popular in mono green. Stomper decks have lots of ramp in them, and aim to cast big creatures to wreak havoc to the opponents.