I'd say 20 at least with tier 3 runes. Its not just being able to kill the creeps, but to do it in a timely manner. Had a few level 12isj WW junglers and they'd often be 2-3 levels behind the non solo-lane enemy champs. Fell behind quickly.
--- "Hockey fans usually have names like Lenny while Nba fans have names like Carl." - room temperature
My summoner level is now 10... and I can jungle well with Amumu starting around level 6ish. Not really efficiently then, but if you go Golem first, it doesn't really matter. I'm sure it is a lot faster with T3 runes, though. --- HG: 1505-8210-4297 GameFAQs moderation failure: http://i77.photobucket.com/albums/j43/king_wallace/GG/moderation.jpg