The Rectyne monopod was an animal which could weigh up to two metric tons.
Chief Miles O'Brien once saw Klingon painstiks used on this creature, the multi-ton animal was so shocked by a single touch of the device that it jumped, in O'Brien's estimation, almost five meters. The painstiks created extreme cephalic pressures in the animal – its head eventually exploded. (TNG: "The Icarus Factor")
The term monopod suggests a single-footed creature.