Flytrap

Flytraps are a type of enemy in Luigi's Mansion: Dark Moon. Found in Haunted Towers and Treacherous Mansion, they attack Luigi and do about ten hearts of damage by swallowing him whole when they see him. They can be stunned for a brief time with the Strobulb, but are otherwise unaffected by Luigi's normal means of attack. To defeat them, Luigi needs to pull a spiky fruit off of a nearby plant using his Poltergust 5000 and shoot it at the plant who will then eat it and die. In the Treacherous Mansion, the same strategy can also be used with a burning chicken to get 20 notes (100G) upon killing one of these plants in the Kitchen.

Reference
Pianta Carnivora