Rivals of Ixalan

Cherished Hatchling | Creature | Dinosaur | When Cherished Hatchling dies, you may cast Dinosaur spells this turn as though they had flash, and whenever you cast a Dinosaur spell this turn, it gains "When this creature enters the battlefield, you may have it fight another target creature." | Sam Rowan

Deeproot Elite | Creature | Merfolk Warrior | Whenever another Merfolk enters the battlefield under your control, put a +1/+1 counter on target Merfolk you control. | Winona Nelson

Giltgrove Stalker | Creature | Merfolk Warrior | Giltgrove Stalker can't be blocked by creatures with power 2 or less. | Chris Seaman

Hardy Veteran | Creature | Human Warrior | As long as it's your turn, Hardy Veteran gets +0/+2. | Suzanne Helmigh

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

Merfolk Mistbinder | Creature | Merfolk Shaman | Other Merfolk you control get +1/+1. | Clint Cearley