Very nice work especially for a first time. The only thing I would've done different is the lines. When doing a realistic tattoo the black outlines aren't necassary. In fact they take away from the design. Instead , try using shadows. Happy Inking x)
snakes are cool, not scary... and this one looks well done :) Agreed that head looks a bit off... like there is no ridge on the snake's left side but there is one on the right...