Ghalta, Primal Hunger

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

Regisaur Alpha

Other Dinosaurs you control have haste.
When Regisaur Alpha enters the battlefield, create a 3/3 green Dinosaur creature token with trample.

Marauding Raptor

Creature spells you cast cost {1} less to cast.
Whenever another creature enters the battlefield under your control, Marauding Raptor deals 2 damage to it. If a Dinosaur is dealt damage this way, Marauding Raptor gets +2/+0 until end of turn.

Forest

Giant Cindermaw

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.

Mountain

Etali, Primal Sickness

Trample, indestructible
Whenever Etali, Primal Sickness deals combat damage to a player, they get that many poison counters. (A player with ten or more poison counters loses the game.)

Etali, Primal Conqueror

Trample
When Etali, Primal Conqueror enters the battlefield, each player exiles cards from the top of their library until they exile a nonland card. You may cast any number of spells from among the nonland cards exiled this way without paying their mana costs.
{9}{G/P}: Transform Etali. Activate only as a sorcery.

Etali, Primal Conqueror // Etali, Primal Sickness

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Polyraptor

Enrage — Whenever Polyraptor is dealt damage, create a token that's a copy of Polyraptor.

Savage Stomp

This spell costs {2} less to cast if it targets a Dinosaur you control.
Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)

Otepec Huntmaster

Dinosaur spells you cast cost {1} less to cast.
{T}: Target Dinosaur gains haste until end of turn.

Form of the Dinosaur

When Form of the Dinosaur enters the battlefield, your life total becomes 15.
At the beginning of your upkeep, Form of the Dinosaur deals 15 damage to target creature an opponent controls and that creature deals damage equal to its power to you.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.