Female Shearwig

Up until Pikmin: Sinister Incinerator only male Shearwigs were ever encountered, the females said to be hiding underground. In the Mountain Springs, a Female Shearwig is encountered as the boss of the Pale Pit of Peril. It is much larger than the male shearwigs and in fact is surrounded by the bugs. It emerges from the ground and lumbers around very slowly, rearing back when it nears Pikmin and then slashing forwards, eating Pikmin. The backside is vulnerable and the attack can be easily sidestepped. The fight gets harder after it takes 50% damage because it will start flapping its wings occasionally to push over your Pikmin. During the entire fight you'll be pestered with male shearwigs as well, which will stop attacking after the female is defeated.

Trivia
The drastic increase in size between the female and male shearwig is similar to the size comparison between the female and male angler fish in real life.

Portal- Kombat