Dragonbroods' Relic
From Tarkir: Dragonstorm set
Dragonbroods' Relic
Artifact
, Tap an untapped creature you control: Add one mana of any color.
, Sacrifice this artifact: Create a 4/4 Dragon creature token named Reliquary Dragon that's all colors. It has flying, lifelink, and "When this token enters, it deals 3 damage to any target." Activate only as a sorcery.