Can this frightening son of a bitch be effective online?

It's weak to a lot of types and has terrible base health and sp.def and has absolutely no speed whatsoever.

It has all the tools it needs to be a very annoying self-healer with all the grass lifesteal moves in its arsenal, and with its fairly high base attack stat it can do some serious damage (and health draining) with Horn Leech

My one big issue though, is high attack/sp.attack fire attackers

Is this guy tough enough to survive a big hit from a fire pokemon on the first turn and come back with health recovery?

And can its Harvest ability be utilized at all to give him more survivability?