Elemer of the Briar

Haste

Whenever Elemer of the Briar attacks, create a
Treasure token. (It's an artifact with "{t}, Sacrifice
this artifact: Add one mana of any color.")
Whenever you sacrifice a Treasure, Elemer of the
Briar gets +1/+0 until end of turn.

Elemer murdered numerous instructors and merchants,
and was known as the Bell Bearing Hunter.