Monster Mix consists of two games: "Monster Mix" and "Monster Express", both of which use cards that show monsters and cards that show only the top, middle or bottom of a monster.

In "Monster Mix", players each hold a monster card in hand and take turns adding monster part cards to the table, trying to assemble the parts they need to match the card they hold. If they do, they score 1 point and take a new monster card. Whoever scores 3 points first wins.

In "Monster Express", all of the monster cards are laid face up on the table, and the top, middle and bottom cards are placed nearby as three decks. One card from each deck is revealed, then players race to grab the monster card that matches the combination of cards shown.