The Skullspore Nexus

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
Whenever one or more nontoken creatures you control die, create a green Fungus Dinosaur creature token with base power and toughness each equal to the total power of those creatures.
{2}, {T}: Double target creature's power until end of turn.

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, Poet of Unity 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

Raptor Companion

Sun-Blessed Mount

When Sun-Blessed Mount enters, you may search your library and/or graveyard for a card named Huatli, Dinosaur Knight, reveal it, then put it into your hand. If you searched your library this way, shuffle.

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.

Knight of the Stampede

Dinosaur spells you cast cost {2} less to cast.

Harnessed Snubhorn

Vigilance
Whenever Harnessed Snubhorn deals combat damage to a player, return target artifact or enchantment card from your graveyard to the battlefield.

Thunderherd Migration

As an additional cost to cast this spell, reveal a Dinosaur card from your hand or pay {1}.
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Ripjaw Raptor

Enrage — Whenever Ripjaw Raptor is dealt damage, draw a card.

Shifting Ceratops

This spell can't be countered.
Protection from blue (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything blue.)
{G}: Shifting Ceratops gains your choice of reach, trample, or haste until end of turn.

Kinjalli's Caller

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

Rotting Regisaur

At the beginning of your upkeep, discard a card.

Pyroceratops

Trample
Whenever you cast a noncreature spell, put a +1/+1 counter on Pyroceratops.

Carnage Tyrant

This spell can't be countered.
Trample, hexproof

The Tarrasque

The Tarrasque has haste and ward {10} as long as it was cast.
Whenever The Tarrasque attacks, it fights target creature defending player controls.

Charging Tuskodon

Trample
If Charging Tuskodon would deal combat damage to a player, it deals double that damage to that player instead.

Titanoth Rex

Trample
Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)
When you cycle Titanoth Rex, put a trample counter on target creature you control.

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal, Primal Tide. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Otepec Huntmaster

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

Quartzwood Crasher

Trample
Whenever one or more creatures you control with trample deal combat damage to a player, create an X/X green Dinosaur Beast creature token with trample, where X is the amount of damage those creatures dealt to that player.

Siegehorn Ceratops

Enrage — Whenever Siegehorn Ceratops is dealt damage, put two +1/+1 counters on it. (It must survive the damage to get the counters.)

Thrasta, Tempest's Roar

This spell costs {3} less to cast for each other spell cast this turn.
Trample, haste
Trample over planeswalkers (This creature can deal excess combat damage to the controller of the planeswalker it's attacking.)
Thrasta, Tempest's Roar has hexproof as long as it entered this turn.

Rampaging Brontodon

Trample
Whenever Rampaging Brontodon attacks, it gets +1/+1 until end of turn for each land you control.

Ghalta and Mavren

Trample
Whenever you attack, choose one —
• Create a tapped and attacking X/X green Dinosaur creature token with trample, where X is the greatest power among other attacking creatures.
• Create X 1/1 white Vampire creature tokens with lifelink, where X is the number of other attacking creatures.

Wakening Sun's Avatar

When Wakening Sun's Avatar enters, if you cast it from your hand, destroy all non-Dinosaur creatures.

Runic Armasaur

Whenever an opponent activates an ability of a creature or land that isn't a mana ability, you may draw a card.

Kalamax, the Stormsire

Whenever you cast your first instant spell each turn, if Kalamax, the Stormsire is tapped, copy that spell. You may choose new targets for the copy.
Whenever you copy an instant spell, put a +1/+1 counter on Kalamax.

Temple Altisaur

If a source would deal damage to another Dinosaur you control, prevent all but 1 of that damage.

Orazca Frillback

Silverclad Ferocidons

Enrage — Whenever Silverclad Ferocidons is dealt damage, each opponent sacrifices a permanent of their choice.

Kinjalli's Sunwing

Flying
Creatures your opponents control enter tapped.

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.)

Polyraptor

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

Priest of the Wakening Sun

At the beginning of your upkeep, you may reveal a Dinosaur card from your hand. If you do, you gain 2 life.
{3}{W}{W}, Sacrifice Priest of the Wakening Sun: Search your library for a Dinosaur card, reveal it, put it into your hand, then shuffle.

Snapdax, Apex of the Hunt

Mutate {2}{B/R}{W}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Double strike
Whenever this creature mutates, it deals 4 damage to target creature or planeswalker an opponent controls and you gain 4 life.

Gishath, Sun's Avatar

Vigilance, trample, haste
Whenever Gishath, Sun's Avatar 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.

Frenzied Raptor

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.

Goring Ceratops

Double strike
Whenever Goring Ceratops attacks, other creatures you control gain double strike until end of turn.

Kaheera, the Orphanguard

Companion — Each creature card in your starting deck is a Cat, Elemental, Nightmare, Dinosaur, or Beast card. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Vigilance
Each other creature you control that's a Cat, Elemental, Nightmare, Dinosaur, or Beast gets +1/+1 and has vigilance.

Forerunner of the Empire

When Forerunner of the Empire enters, you may search your library for a Dinosaur card, reveal it, then shuffle and put that card on top.
Whenever a Dinosaur you control enters, you may have Forerunner of the Empire deal 1 damage to each creature.

Ancient Imperiosaur

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Trample, ward {2}
Ancient Imperiosaur enters with two +1/+1 counters on it for each creature that convoked it.

Ranging Raptors

Enrage — Whenever Ranging Raptors is dealt damage, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Huatli, Dinosaur Knight

+2: Put two +1/+1 counters on up to one target Dinosaur you control.
−3: Target Dinosaur you control deals damage equal to its power to target creature you don't control.
−7: Dinosaurs you control get +4/+4 until end of turn.

Ghalta, Stampede Tyrant

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

Illuna, Apex of Wishes

Mutate {3}{R/G}{U}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying, trample
Whenever this creature mutates, exile cards from the top of your library until you exile a nonland permanent card. Put that card onto the battlefield or into your hand.

Regal Behemoth

Trample
When Regal Behemoth enters, you become the monarch.
Whenever you tap a land for mana while you're the monarch, add an additional one mana of any color.

Tetzimoc, Primal Death

Deathtouch
{B}, Reveal Tetzimoc, Primal Death from your hand: Put a prey counter on target creature. Activate only during your turn.
When Tetzimoc enters, destroy each creature your opponents control with a prey counter on it.

Raging Swordtooth

Trample
When Raging Swordtooth enters, it deals 1 damage to each other creature.