Ghorminath, the Living Dungeon

Whenever a creature an opponent controls enters
the battlefield, create a colorless trap artifact
token with {t}: sacrifice this artifact, deal 3
damage to target attacking creature
When Ghorminath, the Living Dungeon dies,
give each opponent a colorless treasure artifact
token with {t}: sacrifice this artifact, add
one mana of any color to your mana
pool for each creature that player controls