Doom and Gloom Girls

When Doom and Gloom Girls is blocked you may
discard a card; if you do, you may have target
creature you control fight the creature blocking
Doom and Gloom Girls. The blocking creature
takes damage from both creatures and both
defender's creatures take damage from the blocker.
"Guess now you know why we're called the Doom
and Gloom Girls!" - Doom and Gloom Girls, Ep. 40