Life Finds a Way

Whenever a nontoken creature you control with power 4 or greater enters, populate. (Create a token that's a copy of a creature token you control.)

Savage Order

As an additional cost to cast this spell, sacrifice a creature with power 4 or greater.
Search your library for a Dinosaur creature card, put it onto the battlefield, then shuffle. It gains indestructible until your next turn.

Indominus Rex, Alpha

As Indominus Rex, Alpha enters, discard any number of creature cards. It enters with a flying counter on it if a card discarded this way has flying. The same is true for first strike, double strike, deathtouch, hexproof, haste, indestructible, lifelink, menace, reach, trample, and vigilance.
When Indominus Rex enters, draw a card for each counter on it.

Commune with Dinosaurs

Look at the top five cards of your library. You may reveal a Dinosaur or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Carnage Tyrant

This spell can't be countered.
Trample, hexproof

Grim Giganotosaurus

{10}{B}{G}: Monstrosity 10. This ability costs {1} less to activate for each creature with power 4 or greater your opponents control. (If this creature isn't monstrous, put ten +1/+1 counters on it and it becomes monstrous.)
When Grim Giganotosaurus becomes monstrous, destroy all artifacts and creatures other than Grim Giganotosaurus.

Spitting Dilophosaurus

Whenever Spitting Dilophosaurus enters or attacks, put a -1/-1 counter on up to one target creature.
Creatures your opponents control with -1/-1 counters on them can't block.