>>36861609Turtwig is blind (no stair sensor/map surveyor) and can be fucked over by statuses (no nonsleeper/self curer).
Its move pool is okayish. Fucktons of HP draining + Synthesis so you basically can throw Oran Berries at Wynaut, Curse if you like that Def/Atk boosts, early line of sight move in Razor Leaf (that you can replace with Energy Ball for more accuracy and power) and Bite/Crunch to OHKO those pesky ghosts and Drowzee/Hypno if you encounter it.
When it comes to IQ, it's really cheap and sturdy one. Defensive skills, lot of utility in form of Deep Breather, Energy Saver, Survivor etc so you barely use any Max Elixirs and Apples, and when you actually need to eat something at like floor 30-40, you can get by by eating literal shit. Sure-Hitter is pretty nice against evasive foes and for killing trash with regular attacks without wasting time and PPs.
Grass typing makes you resistant to enemy Earthquakes, Earth Powers and Discharges - the most common room-wide moves.
Overgrow ability is nothing special. The only nice use of it is getting fully healed with fucking Absorb/Mega Drain when you kill something on low hp.
But Turtwig really shines when you evolve it to Torterra. Then it gets access to Earthquake that annihilates any monster house in 2-3 tries because you are blind and you won't hit everything with just one use, and coverage in form of accurate Rock Slide from TM if you don't care about Curse anymore.
It's basically cheap as fuck pokemon to use that can successfully run most dungeons completely solo barehanded. The only things that fuck you over are statuses/traps.
I've had great success running Rock Slide, Mega Drain, Energy Ball and Earthquake on Torterra.