Hoshigaki Kisame was introduced alongside Uchiha Itachi, as
one member of the dreaded Akatsuki.
Not much is currently known about Kisame, other than his past affiliation with Momochi Zabuza in Hidden Mist's Seven
Legendary Swordsmen group. He has a freakish personality and equally
freaky appearance.
He has a terrifying sword he calls Samehada, which sucks up Chakra being built inside the body, and rather than slicing it's intended victim, it rips them apart like the teeth of a
shark.
He loves to fight, and was eager to fight Asuma, Kurenai, and
Gai, but was only merely disappointed when Itachi ordered a retreat. He is fearless, and not afraid to use his Samehada liberally. Truly someone to be cautious, if not feared by.