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.
Nobody recognizes him, because his face looks like bear vomit. He also stared in the hit musical cats, as some ugly guy who didn't fit in. He wears beautiful unicorn hair shirts under his Akatsuki robe, and sings phantom of the opera in the shower. He is ugly. Nobody loves him.