Female yellow-lipped sea kraits are longer than males. Females can grow up to the length of 1.6 meters, while males grow up to the length of 1 meters. Yellow-lipped sea kraits are light or dark blueish-grey on the top and yellow underneath with black bands running down the body and tail. The upper lip and snout is yellow (hence its name) while the rest of the head is black. They are very venomous but they are not aggressive and rarely ever bite divers or swimmers.