Volatile Dweevil
Mandarachnia explodus
The Volatile Dweevil is a kind of enemy in the Pikmin 2 game. They resemble walking bomb-rocks except that they are dweevils. Unlike other Dweevils, they will start to detonate as soon as they start walking. They are also known to drop from ceilings. The only way to kill it is to run and wait for it to detonate, although if you are in peril you may use ultra-bitter spray to petrify it and then kill it. You will at least get nectar, or possibly spray.
Olimar's Notes
The Volatile Dweevil is one member of an insect family known for mimicking objects by carrying them on their backs. The dweevil family exhibits a most unusual characteristic whereby the creature's behavioral patterns actually changed based upon the object the creature carries on its back. The Volatile Dweevil has one of the most potent of all the species within the dweevil family, due to the habit of carrying explosive devices. Approach with caution and/or body armor!
Louie's Notes
The scorching species combusts upon contact with the tongue. Only edible by the adventurous and asbestos-tongued.
How to Kill
Pikmin
Don't use Pikmin, they likely won't live.
Captains
Run up to it and punch it once, then run. That way, it'll explode while you're away.