It was lame when Kobe Bryant nicknamed himself as the "Black Mamba." I mean no one ever nicknames themselves and have it actually stick. There is probably an unwritten rule somewhere that forbids it. But this is Kobe Bryant we are talking about, when he gives himself the nickname, he plays the full part. I will let Jordan Crawford explain it to you.
From DC Sports Blog:
On Kobe Bryant’s noises: “When I (Jordan Crawford) first played with Kobe — they call him the Black Mamba — but then he was doing like a little snake sound when he wanted the ball. It was crazy. It was crazy. It’s like tsssss, tsssss. Like fishing. Tsssss, tssss. He do that. Everybody tells you he’s gonna do it before you play him — like, ‘Wait till you hear him do this.’ And then he [does] it, and it’s like, what? He’s really a mamba. It sounds like some kind of snake.”You see, Kobe Bryant is dedicated to perfect every single one of his crafts. Whether it be his jump shot, not playing defense or his nickname. He will master it. So when he gave himself the "Black Mamba" title, he knew what he was in for and if hissing was what he needed to do to keep the name, the man will do it.