Wild Monster is a Spell Card introduced in Boss Monster: The Next Level
This card is meant as a surprise attack, of sorts, for a hero going through your dungeon. It is a good card to use when a player has built a weaker room down to activate its Build effect, and the player wishes to place down a stronger Monster Room over it.
It is unknown whether the player can activate this when a Hero is currently in a room the player wishes to build over, and, if they can, whether the newly built Monster Room can deal damage. It is a matter that is up for debate until the release of the Advanced Rules for The Next Level.
The artwork of this card take a very different approach from the normal side-scrolling style artwork of most of the cards in Boss Monster. The scene appears more akin to the artstyle in a Pokemon battle from the third generation games, Pokemon Ruby and Sapphire. It even features a fire-type looking hyena monster.
Marius, a popular subject in some Spell cards, makes an appearance in this card's artwork.