Its Gaze ability can put party members to sleep, however as carbuncle tends to only use physical attacks aside from that, there is little negative impact from this ability. Carbuncle also has notably higher defense than other enemies in the area, attacks doing roughly a third less than what they would normally, however they are still easy to take out due to their low HP.
Carbuncle was a mythical creature reportedly sighted in the Americas by Spanish conquistadors. It is described as a small creature, either a bird or a mammal, that has a gem in its forehead crystallized from the brain of a dead dragon. According to myth, it is good luck to catch a carbuncle. A carbuncle is also an archaic name given to any red cabochon cut gemstone. The name applied particularly to red garnet.