rengar or hecarim?

rengar. reasoning: cats belong in the jungle, horsies naturally belong in open fields

With the changes in S5 hecarim is actually becoming more of a top laner (goggle it. Its new, but its a thing) so for jungle I might say rengar. Of course it really depends on what your looking for in a jungle. Hecarim has more utility, tankyness, and engage potential than rengar (depending on how you build them both of course), but rengar has the damage and snowball potential to carry games harder than hecarim.

So basically if you want a safer pick who you can be just as useful without being fed go hecarim, but if you want the really heavy damage and the carry potential that comes with it go rengar.