Fangroot Garden is a Monster Room that will be introduced in Boss Monster 2.
Strategy
This card is best played in the later rooms of a dungeon (rooms 3 to 5) so as to make use of the effect of the card, since it allows a better chance for a Hero to die in this room. This card can also allow a quicker use of a Boss's Level Up ability.
Trivia
The Brothers had originally called this Room "Carnivine Garden", but later remembered that was a Pokemon.