Indoraptor, the Perfect Hybrid

Bloodthirst X (This creature enters with X +1/+1 counters on it, where X is the damage dealt to your opponents this turn.)
Menace
Enrage — Whenever Indoraptor is dealt damage, choose an opponent at random. Indoraptor deals damage equal to its power to that player unless they sacrifice a nontoken creature of their choice.

Urban Daggertooth

Vigilance
Enrage — Whenever this creature is dealt damage, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sun-Crowned Hunters

Enrage — Whenever this creature is dealt damage, it deals 3 damage to target opponent or planeswalker.

Ripjaw Raptor

Enrage — Whenever this creature is dealt damage, draw a card.

Apex Altisaur

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

Silverclad Ferocidons

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

Ranging Raptors

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

Snapping Sailback

Flash
Enrage — Whenever this creature is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Raptor Hatchling

Enrage — Whenever this creature is dealt damage, create a 3/3 green Dinosaur creature token with trample.

Needletooth Raptor

Enrage — Whenever this creature is dealt damage, it deals 5 damage to target creature an opponent controls.

Vrondiss, Rage of Ancients

Enrage — Whenever Vrondiss is dealt damage, you may create a 5/4 red and green Dragon Spirit creature token with "When this token deals damage, sacrifice it."
Whenever you roll one or more dice, you may have Vrondiss deal 1 damage to itself.

Polyraptor

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