theres a simple trick to snake boss, i used to do it all the time. go kill the elemental boss first (go via snake boss but dont kill snake boss). make sure all the trash is cleared between the elemental guy and snake guy. Position your team (except tank) in front of the altar by elemental guy. Now go aggro the snake boss with your tank and run like hell to your team (if you are a pally you can bubble, dont have earth shield up though so pally keeps aggro).

When you fight him at the elemental guy you can usually kill him before a snake even makes its way to your team. This is similar to the strat of fighting him up the stairs, but for whatever reason I found it easier to fight him at the elemental boss. You will also get the achievement for not getting wrapped.