Familiar is permanently a mustard jelly

CrazyFind

To keep your imp familiar a mustard jelly is simple. First: summon imp, second: have imp cast poly self, third: poly into mustard jelly, fourth: have character speak to familiar and slap it in the head twice and an option to put familiar in pack should appear. If it doesn't then repeat the head slaps until it does. Once familiar is in pack: rest and save game. After saving game exit game and reload the save. Finally release familiar from pack and you have a permanent mustard jelly. The option to change shapes is gone but it doesn't matter, the jelly is by far the best form. The spell will never wear off and can't be dispelled. It can be put back in the pack by slapping it in the head enough times. It can still be killed, but not by anything that doesn't strike as a +1 weapon or better. It has 125% magic resistance so spell casters aren't much concern... Enjoy

Yigor

Interesting, but not necessary imho. Other forms are sometimes useful too, for example, Flind with Fire Halberd. 👈

CrazyFind

I haven't tried it with any other form, but I'm sure it'll work. I like the mustard jelly because I like to solo sorcerer or dragon disciple and it makes a great shield because most things in BGEE can't hit it. I found out that the breath weapon of the dragon disciple isn't considered magic and will kill your familiar...
The +3 aspect of the flind's weapon is nice. I'll look into trying that option out.