Trample Domain — Whenever this creature deals combat damage to a player, put X +1/+1 counters on target creature you control, where X is the number of basic land types among lands you control.

This creature enters with X +1/+1 counters on it. {2}: Put a +1/+1 counter on this creature, then you may reselect which player this creature is attacking. Only the player this creature is attacking may activate this ability and only during the declare attackers step. (It can't attack its controller.)

Vigilance Hydra spells you cast cost {4} less to cast. Whenever a creature you control becomes the target of a spell, Gargos fights up to one target creature you don't control.

Grakmaw enters with three +1/+1 counters on it. Whenever another creature you control dies, if it had a +1/+1 counter on it, put a +1/+1 counter on Grakmaw. When Grakmaw dies, create an X/X black and green Hydra creature token, where X is the number of +1/+1 counters on Grakmaw.

Polukranos enters with six +1/+1 counters on it. It escapes with twelve +1/+1 counters on it instead. If damage would be dealt to Polukranos while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from it. {1}{B}{G}: Polukranos fights another target creature. Escape—{4}{B}{G}, Exile six other cards from your graveyard.