Crawl

This achievement is awful.

Out of all the Taunting achievement, this one is - by far - the hardest, in my opinion.

When you go to start the game, select "No One" when asked to pick your God. You will then be allowed to taunt a God instead. Choose S'hrim.

Taunting S'hrim starts you with an artifact that causes insanity and also periodically turns you into a frog.

Insanity - Every time you try to move, you begin to sob after a few steps. While sobbing, you can barely move, you are so slow. You can attack or use your special ability (such as roll) to cancel the sob, but it is very hard to play this way.

Frog - To make matters worse, you periodcally turn into a frog. While you are a frog, your health is drastically reduced and you can only hop around - again, very slowly. If you get hit even a couple times while in frog-form, you will die. After a few seconds of frog, you turn back into human. The amount of time you have before you next turn into a frog seems to be random. When you are about to turn, you will see green gas coming out of you for a second. This gives you just a moment to prepare.

I had the hardest time with this achievement. Kill-stealing when you are a monster still works, so it is not very difficult to get to a high level if you are good at doing that.

However, I found it to be ridiculously difficult to beat any of the bosses while insane and constantly frogging,

Luckily, there is one "exploit" you can use, which makes this achievement so much easier.
There exists a single artifact that can RANDOMLY spawn in the shop that you can purchase that switches all of your equipment with a random hero. If you see this artifact, purchase it immediately. Since the insane/frog is an artifact you start with, you will give it (and your other equipment) to a random AI and take their equipment instead.

There is nothing you can do to make this artifact spawn. Just keep playing and hope you are lucky.

As mentioned in my Gor achievement, I assume this "exploit" is not intended behavior. Getting rid of the curse/insanity is surely not intended. If you want this achievement, may be better to do it now in case this gets patched.