Trample
Goblin Mutant can't attack if defending player controls an untapped creature with power 3 or greater.
Goblin Mutant can't block creatures with power 3 or greater.
Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)
When you control a Dwarf, sacrifice Goblins of the Flarg.
When Hecatomb enters the battlefield, sacrifice Hecatomb unless you sacrifice four creatures.
Tap an untapped Swamp you control: Hecatomb deals 1 damage to any target.