>>46753379Can't be THAT bad. Leech Life is super effective against the bugs in viridian forest in gen 1, so training on cocoons isn't the worst experience out there.
Confuse Ray, Toxic, Mega Drain, Bite/Swift/Take Down/Double Team makes it doable with a few dozen restarts. You can swap out the last few moves through TMs in the E4 to cover for the more difficult parts. If all else fails, struggle is an option for anything that's not ghost.