For my all-combat Vampire army I had a Lord on Abyssal Terror in mind.
Reading the description it could look like any monster in the Warhammer World
So conversions are unlimited.

My three favourites are an Orc Wyvern, A Dark Elf Manticore
and Louen Lionheart. The last one maybe easiest as I'd put a Chaos Helmet on his head.

If you have an Abyssal Terror, what does he look like or
What would you want it to look like? Maybe a Lizardmen Carnosaur?