Shroomisaur
Smogon's fantastical fun-guy.
MmmmmMMM! Delicious. I can't wait for Crobat to make his return.Crobat is definitely a pokemon to watch out and every stall team must be prepared to deal with it.
It has Infiltrator, for starters, meaning Subs won't stop it.
It has Defog, so it's going to remove your entry hazards.
It has U-Turn, meaning it can't be trapped with Infestation.
It's a Poison-type, so you can't Toxic it.
It has Hypnosis, which has 80% accuracy after a -1 evasion drop from Defog. It also goes through Substitute thanks to Infiltrator.
And the cherry on top is its 130 base speed and access to Taunt, so unless you're running a Prankster or base 130+ speed Sleep Talker, you can't even use it to absorb Hypnosis.
As for stall, there definitely needs to be discussion now that we know Defog removes hazards on both sides. How will this impact stall teams? You certainly can't rely on a spinblocker to keep hazards up anymore, so this means you're going to have to protect your hazard setters throughout the match in case they are removed. Defog is also a much bigger nerf to Spikes and Toxic Spikes, as one Defog is guaranteed to remove multiple turns of work setting them up. I think this means stall teams will favor Toxic itself over TSpikes now... and Crobat just so happens to be one of the best users of Toxic there is, with perfect accuracy and being able to hit behind subs.