Vampire Requiem Knight (Vampire Monster and Werewolf Transformations)

This trippy Franco-British comic, recommended by Andréssaurio Rex, features a vampire/beast transformation in volume two:

While volume three has a lycanthropic reversion and transformation:

 

American Vampire (Monster/Vampire Transformations)

Thanks again to Andréssaurio Rex for this recommendation. The vampires in this comic can transform into monster/ghoul forms, as you'll see below.

From issue 11:

From issues 26 & 27, an old-man ghoul:

His reversion: 

My Instant Death Ability is Overpowered (Vampire-Werewolf Transformation)

In episode four of this anime a monster-villain starts transforming and grows claws, a wolf muzzle, and bat-wings. But the hero's instant death ability strikes before the transformation can finish. His companion is right to be irritated!

Fright Night (Wolf Reversion & Bat Transformations)

Everyone is familiar with Evil Ed's excellent wolf reversion scene from Fright Night, but you might not know that the film was adapted into a comic series in 1988. From issue 2:

As usual in comics, Evil Ed was somehow brought back to life, and he's seen reverting from bat form in issue 8:

He turns into the green bat again in issue 17:

There's also a basketball player who turns into a vampire: 

Le Prince de la Nuit (Vampire Bat Transformation)

Tome 3 of this French comic features a vampire turning to bat form before his destruction:

Morbius: The Living Vampire (Vampire, Rat, and Hawk Transformations)

 My thanks to Vanzilen on our Discord channel for recommending this 5 issue limited series. In the first issue of Morbius: The Living Vampire the title character tries finding a cure for his condition but instead turns himself into an even more monstrous vampire:

In issue 4 Morbius grows even more bloodthirsty and bat-like:

And to make things worse, a super-villain is conducting experiments to transform people into animals. He gets off to a good start by turning a man into a rat:

In issue 5 Morbius confronts the villain, who uses the serum on himself to become a dog-man and fight Morbius:

Unable to cure the villain, Morbius eventually devises an effective cure:

He tests the new cure on a hawk-man, who reverts to normal:

The Witcher 3 (Vampire/Monster Transformation)

Kumaguma here with a transformation from The Witcher 3, particularly from the Blood and Wine expansion pack. Here is the higher vampire, Dettlaf, transmogrifying into his bat form while battling Geralt: