Jellicent doesn't actually counter Tentacruel though. If Tentacruel has Toxic, it's plain losing, while if it has Toxic Spikes, it easily sets up Toxic Spikes in Jellicent's face, then switches out to a Pokemon that forces pringles out. Next time it comes in, it's screwed. It's kind of like how Giratina doesn't counter Forretress, since Forry just set hazards up in its face and you end up in a losing position anyway. I guess you could say "If Jellicent has a Toxic Spikes absorber on its team (opposing Tentacruel, Toxicroak, Nidoqueen)", then it's a good check, but otherwise, it doesn't work.
Furai i rule f****s
20:09 Melee_Mewtwo wow
20:09 Melee_Mewtwo the furry is lord of the gays