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.)

Sunfrill Imitator

Whenever this creature attacks, you may have it become a copy of another target Dinosaur you control, except its name is Sunfrill Imitator and it has this ability.

Itzquinth, Firstborn of Gishath

Haste
When Itzquinth enters, you may pay {2}. When you do, target Dinosaur you control deals damage equal to its power to another target creature.

Kinjalli's Caller

Dinosaur spells you cast cost {1} less to cast.

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.