Selesnya Signet

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.

Gruul Cluestone

{T}: Add {R} or {G}.
{R}{G}, {T}, Sacrifice Gruul Cluestone: Draw a card.

Gruul Signet

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.

Zetalpa, Primal Dawn

Flying, double strike, vigilance, trample, indestructible

Verdant Sun's Avatar

Whenever Verdant Sun's Avatar or another creature you control enters, you gain life equal to that creature's toughness.

Apex Altisaur

When Apex Altisaur enters, it fights up to one target creature you don't control.
Enrage — Whenever Apex Altisaur is dealt damage, it fights up to one target creature you don't control.