The Bearded Amprat is a rodent-like creature in Pikmin 3. The creature passively walks around until a Pikmin or a Captain come close, it will then begin to rapidly rub its beard, generating electricity, which causes its hair to flare up and reveal its mouth, it will then charges and try to eat them. When he is charging, its body will be electrified and only Yellow Pikmin will damage it.
Pikmin 3 Website
"A fearsome creature capable of sending out electric shocks to fend off any Pikmin brave enough to come into contact with it."