Unlike the other Plagas who burst from the neck, the Duvalia species destroys its hosts entire upper body when it emerges. It appears as a large flower-like parasite with thick armor on the outside of its body. Its weak points are the fleshy "tail" that hangs off its back (the remains of the host's upper torso/ribcage), and the fleshy core of the shell, which is only exposed when the Duvalia is about to attack the player or if shot in the legs repeatedly.[excerpt 1] In addition to these, and the usual weakness to bright light, a Duvalia can be blown to pieces with a single hand grenade if the explosive hits the core. It is also the type of Plaga with the least appearances of all.
Due to its lack of arms and heavy shell, the Duvalia is one of the only foes in the entire game who cannot jump or climb. However, in the Mercenaries minigame, the Duvalia gains the ability to jump across gaps and walk up stairs, although ladders are still impassable obstacles for it.