Hell Mongrel
From Modern Horizons 2
Card details
Creature — Nightmare Dog
Common
Discard a card: Hell Mongrel gets +1/+1 until end of turn.
Madness 
(If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
It feeds on shadows, fear, and blood.
Artist: Robbie Trevino
Card details
Creature — Nightmare Dog
Common
Discard a card: Hell Mongrel gets +1/+1 until end of turn.
Madness (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
It feeds on shadows, fear, and blood.
Artist: Robbie Trevino
All versions of Hell Mongrel
