Nessus, the Impure

Whenever Nessus attacks, you may tap
target creature.
Deianeira, Hercules's lover, was afraid he was falling for someone else. She dipped a shirt in the blood of Nessus. She realized it was poisonous,
but it was too late and Hercules had already
worn the shirt. His skin started to burn and he threw himself in a pyre.