Iron Pillbug

The Iron Pillbug is a species of parasick that curls into an impenetrable ball when threatened.

=In fanon games=

In Pikmin: Spark
Iron Pillbugs are a species of parasick appearing in Pikmin: Spark. They are small, oblong isopods roughly the same size as their distant relative, the Mitite, and are covered in curved segmented plating similar in strength to metal. The armor of an Iron Pillbug grants it full immunity to Purple Pikmin pounds and Rock Pikmin throws. Being docile and shy creatures, Iron Pillbugs normally spend their time acting as harmless filter-feeders; that is, until Pikmin family or enemies invade their personal space, which causes them to curl into a ball, and rendering them invincible. Swarming an Iron Pillbug while it is in such a state causes it to retaliate by dashing forward in a straight line, crushing anything in its path, until hitting a sizeable obstacle. Upon doing so, it has a small chance of flipping onto its back from the impact and briefly becoming vulnerable. Some predators such as bulborbs take advantage of these attributes by roaring at an Iron Pillbug to scare it into hiding and then kicking it to expose it to harm. A scared Iron Pillbug eventually unfurls itself after being left alone for long enough. Iron Pillbugs do not offer many rewards upon defeat despite the convoluted process required to kill them, so the only real use they have is to help complete the Creature Log.