Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters the battlefield with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Pantlaza, Sun-Favored

Whenever Pantlaza, Sun-Favored or another Dinosaur enters the battlefield under your control, you may discover X, where X is that creature's toughness. Do this only once each turn. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Ghalta, Stampede Tyrant

Trample
When Ghalta, Stampede Tyrant enters the battlefield, put any number of creature cards from your hand onto the battlefield.

Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample

Dinotomaton

Menace (This creature can't be blocked except by two or more creatures.)
When Dinotomaton enters the battlefield, target creature you control gains menace until end of turn.