Break Out

Look at the top six cards of your library. You may reveal a creature card from among them. If that card has mana value 2 or less, you may put it onto the battlefield and it gains haste until end of turn. If you didn't put the revealed card onto the battlefield this way, put it into your hand. Put the rest on the bottom of your library in a random order.

Forest

Pugnacious Hammerskull

Whenever this creature attacks while you don't control another Dinosaur, put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

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.

Trumpeting Carnosaur

Trample
When this creature enters, discover 5.
{2}{R}, Discard this card: It deals 3 damage to target creature or planeswalker.

Bonehoard Dracosaur

Flying, first strike
At the beginning of your upkeep, exile the top two cards of your library. You may play them this turn. If you exiled a land card this way, create a 3/1 red Dinosaur creature token. If you exiled a nonland card this way, create a Treasure token.

Mountain

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Intrepid Paleontologist

{T}: Add one mana of any color.
{2}: Exile target card from a graveyard.
You may cast Dinosaur creature spells from among cards you own exiled with this creature. If you cast a spell this way, that creature enters with a finality counter on it. (If a creature with a finality counter on it would die, exile it instead.)

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

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.

Ixalli's Lorekeeper

{T}: Add one mana of any color. Spend this mana only to cast a Dinosaur spell or activate an ability of a Dinosaur source.

Copperline Gorge

This land enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Monstrous Rage

Target creature gets +2/+0 until end of turn. Create a Monster Role token attached to it. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample.)

Kogla and Yidaro

When Kogla and Yidaro enters, choose one —
• It gains trample and haste until end of turn.
• It fights target creature you don't control.
{2}{R}{G}, Discard this card: Destroy up to one target artifact or enchantment. Shuffle this card into your library from your graveyard, then draw a card.

Tranquil Frillback

When this creature enters, you may pay {G} up to three times. When you pay this cost one or more times, choose up to that many —
• Destroy target artifact or enchantment.
• Exile target player's graveyard.
• You gain 4 life.

Rockfall Vale

This land enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Belligerent Yearling

Trample
Whenever another Dinosaur you control enters, you may have this creature's base power become equal to that creature's power until end of turn.