If you disregard supernatural powers of undead, it’s different depending on who you ask anyway, I’d go with a skeleton.

Arch lich?

Lich would be fun

I’m pretty lazy, so… spectre. Having no body to haul around will make things easier.

A vampire. Since it’s a necromancer raising me, instead of another vampire, I won’t be enthralled and will have free will.
Then there’s all the wonderful abilities and the fact that I’ll still look good for an undead (it’s a pretty movie vampire, not one of those creepy ones)

So any animal is fair game? In which case, dodo. You MFs ate us into oblivion, I’m gonna come back with species worth of pent up rage and an undead thirst for blood.

Edit: in retrospect I now realise a dodo would be super easy to send back to the underworld :-(. I’m gonna be… checks deadliest thing notes, a car.

A bowl of petunias.

Hmmm,an undead deity, undead tarrasque, or, the pact to summon me would be the life of the summoner and he summons me as his undead self.

I like all of these options

Probably like a skunk or something idk.

I’d come back as a wraith, preferably shadow of mordor / war style with domination powers.

Otherwise, a lich assuming I could have lich magic and evolve

Dracolich

Wraith, so that I can go through walls, carry a big-ass scythe, and upgrade from generating Fear to generating Terror, so I can exploit that juicy morale penalty even if the enemy unit is immune to Fear.

If I’m an undead undead, do I get to live?

Ghost. Flying, intangibility, spooky telekinesis … Sounds great.

Lich. The power that other famous examples like Darth Cheney and Henry Kissinger had is just too tempting.