CM
Adventurer
Now I have an idea for a Lich with a Flameskull familiar.
4e had flaming skull familiars (and also the non-flaming variety). A tiefling wizard in my last campaign made a familiar out of the skull of a (now nearly-powerless) lich they defeated. The two didn't really get along (but it always followed the letter of his orders) and it was constantly tempting him to use necromatic spells, so he eventually destroyed it and retrained the feat into something else.
It made for quite a sight when he'd get the skull out of his backpack at taverns and start talking strategy with it.