Green Goblin, Back for More {3}{B}{B}
Legendary Creature — Goblin Human Villain
BlackCommander: legal
Identity
Black
EDHREC rank
#18,443
Cheapest printing
US$0.59
TCGplayer
Printings
1
Flying, menace
At the beginning of combat on your turn, you may discard a card. If you do, each opponent discards a card.
Mayhem {3}{B}{B} (You may cast this card from your graveyard for {3}{B}{B} if you discarded it this turn. Timing rules still apply.)
Every printing
highest TCGplayer market first; a card with only a thin single listing shows its low
In short
A Commander deck is a commander and 99 other cards, one copy of each (except basic lands), all inside the commander's colour identity. Paste a full list into the deck price calculator to price it and check it against the format.