Lulu's Polymorph changes the enemy into a squirrel for a few seconds, slowing them down, and also preventing them from attacking and using abilities.

![example of polymorph](https://i.stack.imgur.com/bPl2G.jpg)

It seems to cancel some abilities, like Death Lotus from Katarina, or Warwick's ultimate.

However, there are a lot of other abilities which are not cancelled, and keep going even during the polymorph. This leads to strange effects, like for example a squirrel running after you with a circle of fire around him (Mundo) or a sword spinning (Garen). It also doesn't cancel Fiddlestick's ultimate, once he teleported.

You would expect someone changed as a squirrel to be unable to do such things. So what exactly can and can't be cancelled by Lulu's Polymorph?