The Balrog, Durin's Bane

Other black creatures you control get +1/+1.

When The Balrog dies, exile instead. When
you do, each player exiles a creature or land
they control. If a player controls a commander, they must exile their commander.

"It was like a great shadow, in the middle of which was a dark form, of man-shape maybe, yet greater;
and a power and terror seemed to be in it and go before it." Tolkien 409