Mantraps are dangerous carnivorous plants found in the Jungle. They are one of the few enemies in the game that can kill a Spelunker instantly, regardless of how much health they have.
They will eat any human or monster their own size that touches them (except other Mantraps), including corpses thrown at them or Spelunkers attempting to stomp on them from above.
Behaviour
Mantraps move slowly and do not jump or fall off ledges.
Having no eyes, they do not directly pursue their prey, so will only kill things that wander into their mouths.
When a Mantrap eats something, the Mantrap will be stunned for a short time as it rests. It does not take damage from being stunned in this way.
Shopkeepers eaten by Mantraps will not be killed, but will simply tear their way out from inside the Mantrap after a short amount of time, killing the plant in the process.
This does not cause the Shopkeeper to become angry, but he will remain angry if the Spelunker is already wanted.
If a Mantrap eats a Fire Frog it will explode. This can anger shopkeepers or Kali .
Strategy
Mantraps are best avoided rather than attacked, due to the high risk of getting close to them and the long time it takes to kill them without a weapon.
If it is necessary to kill a Mantrap - if it is blocking your path or threatening a Damsel, for example - it is best to do so from a distance with a ranged weapon or a throwable object, like a rock. Thrown corpses will be swallowed and deal no damage, but this will still cause the Mantrap to be stunned long enough to slip past it.
Although they can be sacrificed at an Altar while stunned for a decent amount of favor, this should only be attempted if the Altar is very close (within a few tiles) as the Mantrap's stun period is relatively short. If it wakes up while being carried, it will immediately eat the player carrying it.
Mantraps can be used as a situational weapon against tough enemies such as Cavemen or Green Knights by stunning them and throwing them towards the target. When they awaken, there is a good chance that they will devour the other enemy and allow you to pass safely.
Trivia
Obviously, the name of the Mantrap is derived from the Venus Flytrap, a well-known carnivorous plant famous for feeding on insects such as flies.