serperior set

I think that's how you spell serperior snivys final evolution. So I typed in the mystery gift code pokemon497 and get a timide hidden ability serperior and I wanted to know a good move set and ev spread for it

Also could you tell me a good item for it

The item would probally be leftovers, since serperior probally already is kinda bulky. Well it just works xD.
But for the moveset, maybe try running Leaf Storm, Dragon Pulse, and maybe Giga drain, for which type the hidden power could be. I honestly dont know.. Maybe rock? And since Serperior is pretty much a sweeper you should give it ev's in speed and special attack. Or if you wanna go more bulky, do hp or something like that. You'll have to look what fits with you're team.

I disagree with using leftovers. If you want a sweeper, use a life orb. It gives your leafstorm extra power before the boost. You also get more power overall. If you have a bad hidden power, use nature power. By default it's tri attack, with electric terrain it becomes thunderbolt, grassy terrain it becomes energyball, and misty terrain moonblast. The rest should be leafstorm, giga drain and dragon pulse.

Yeah I checked on smogon and they recommended life orb and I went for evs in special attack and speed

try giving it a life orb and gigadrain, dragon pulse, leafstorm, and hidden power rock, fire, or ground.

Instead of hidden power you could also run Secret Power, that turns into Tri Attack. It can really catch your opponent off guard.