Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Gishath, Sun's Avatar

Vigilance, trample, haste
Whenever Gishath deals combat damage to a player, reveal that many cards from the top of your library. Put any number of Dinosaur creature cards from among them onto the battlefield and the rest on the bottom of your library in a random order.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Roar of the Fifth People

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Create two 3/3 green Dinosaur creature tokens.
II — Roar of the Fifth People gains "Creatures you control have '{T}: Add {R}, {G}, or {W}.'"
III — Search your library for a Dinosaur card, reveal it, put it into your hand, then shuffle.
IV — Dinosaurs you control gain double strike and trample until end of turn.

Huatli, Poet of Unity

When Huatli enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{3}{R/W}{R/W}: Exile Huatli, then return her to the battlefield transformed under her owner's control. Activate only as a sorcery.

Huatli, Poet of Unity // Roar of the Fifth People

Zacama, Primal Calamity

Vigilance, reach, trample
When Zacama enters, if you cast it, untap all lands you control.
{2}{R}: Zacama deals 3 damage to target creature.
{2}{G}: Destroy target artifact or enchantment.
{2}{W}: You gain 3 life.

Palani's Hatcher

Other Dinosaurs you control have haste.
When this creature enters, create two 0/1 green Dinosaur Egg creature tokens.
At the beginning of combat on your turn, if you control one or more Eggs, sacrifice an Egg, then create a 3/3 green Dinosaur creature token.

Regisaur Alpha

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

Pantlaza, Sun-Favored

Whenever Pantlaza or another Dinosaur you control enters, 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.)

Earthshaker Dreadmaw

Trample
When this creature enters, draw a card for each other Dinosaur you control.