Kaiju Wolf Transformation (Werewolf-Kaiju Transformation)

This fine animation was recommended by Leone Vukan on our Discord Channel ...and is exactly what the title says:

Monster Raban (Kaiju/Lizard Monster Transformation)

Thanks to Dinonator for recommending this manga from 1958. A scientist comes across his rival, who has been reduced to skin and bones by poison, and injects him with a vial of Godzilla's blood, hoping it will be lethal. Instead it turns his rival into a giant lizard.  

 

Teen Titans: Earth One & Beast Boy: Lone Wolf (Cat, Wolf and Kaiju Transformations)

Teen Titans: Earth One was an alternate universe version of the team, and volume two features a couple Beast Boy transformations. I've re-edited and combined several panels and pages, so please forgive any choppy transitions. 

First we see Beast Boy revert back from wolf form:

Later that night he turns into some sort of cat (or wolf?) when the Titans are attacked:

Lastly, at the climax he turns back into a cat to combat the villain:

Let's switch media but not character, to the animated webseries Beast Boy: Lone Wolf. In this clip Beast Boy plans on taking on Starro but can't get the transformation right and gets depressed. But thanks to a motivational speech from Mikie, he ends up pushing himself to new heights and sizes:

Something about Knuckles (Monster Transformation)

Here are two scenes from a Sonic the Hedgehog fan-animation.

After trying to help Eggman, the hedgehog is tricked and transformed into the same monster that his enemy had transforming into:

Knuckles embeds the shard of the Chaos Emerald into himself, to turn into a monster that can equal Sonic in a last ditch effort:

Asian Cinema Round-Up (Muscle growth, Monster, Kaiju, Alien, and Element Transformations)

Thanks once again to Ian Ricky for curating this list of transformations in Asian superhero, horror, and supernatural films. He's also provided commentary on his selections.

快递侠 (Express Man, 2018)
"Sorry, I don't know much Chinese, so I will translate as much as I can. This is a mainland Chinese movie about ordinary civilians who have superpowers. Near the end of the movie an evil scientist mutates the genes of one of the protagonists, the security chief (played by actor Peng Yan; 彭禺厶), who then turns into a very hot muscular creature named 钢铁侠 (literally Iron Man)."



"Later, Express Man and friends teamed up to free the chief of his evil gene mutation and he reverts  to normal (I don't know why Express Man punched him twice afterward though)."

***

"It's rare to find a movie where a man transforms into a Kaiju, but I've finally found one in the Japanese movie Ultraman the Next (2004). Takafumi Udo (played by actor Kenya Oosumi) has been possessed by a mysterious ball of blue light and starts progressively mutating into a monster after being shot by his fiancee. 

00:00 1st Form - Spiky and Scaly Skin.  00:52 2nd Form - Lizard.   01:09 3rd Form - Idorobia.

02:22 4th Form - Reputiria.  03:26 Normal Form - Human Revert (Shirtless Scene).  

05:06 1st Form - Growing Limbs.  06:05 1st Form - Growing mire Limbs 06:50. 

4th Form - Reputiria.  07:13 5th Form - Beruzebua. 08:30 6th Form - Beruzebua-Korone."

***

Loser Vs. Aliens (小强大战外星人, 2019)
"An alien has terrorrized China! It begins when an alien possesses a man in the factory and then the police chief who captures him (Pujun Han). Then he begins infecting multiple citizens. Near the end, the protagonists finally face him and his mob of infected citizens. He mutates his arm into a crab-like claw and grabs the girl. A boy tries to rescue her by pouring water on the chief; he gets enraged and transforms into a bigger alien (06:20). The boy then decides to cure all the infected by making rain from a water tower. Everyone returns to normal."



***

Cyclops (キクロプス, 1987)
The story of three struggling mutants; Miyuki, her older brother Kyo (Kazuhiro Sano), and a man in sunglasses, Michio Sonezaki (Kai Atô). Miyuki gets pregnant and Sonezaki tries to kill her baby in the hospital. He is confronted by Kyo. The two men turn into mutants and eventually fuse together. Miuyki is also a mutant; at the end she and her baby fuse together.




***

Impossible (不可思异, China, 2015)
Memeda, an alien from outer space, possesses a depressed man named Tang Liguo (Wang Baoqiang) who just lost his daughter in a car accident. When gangsters threaten Liguo, he transforms into the alien. Sadly only the first part of the transformation occurs onscreen.

***

"Mulawin vs. Ravena (2017)  is an Filipino fantasy television series about two races of winged humanoids; Mulawin and the evil Ravenas. Almiro (Derrick Monasterio) is a half-blood Mulawin  who has always been mocked for having a lump on his back. It turns to contain a pair of wings. He later becomes monarch of the Mulawin kingdom of Avila.
Next we see Rafael Montenegro (Kiko Estrada), a half-blood Ravena and the best friend turned nemesis of Almiro. He ends up in the hospital after painfully growing a back lump and future wings. He flies to the Ravena kingdom and becomes its monarch, until Almiro kills him."

"Moon Girl and Devil Dinosaur"and (Dinosaur and Godzilla/Monster Transformations & Reversions)

Two Marvel comics involving reptiles...

A scientific expeirment gone wrong causes a Tyrannosaurus Rex to become a human boy in Moon Girl and Devil Dinosaur #33:

And from New Avengers (Vol.4, # 09) the story "American Kaiju." The American military injects a soldier with a gamma-enhanced cocktail of mutant growth hormones and the serum used by the Lizard from Spider-Man comics. The result? An all-American Godzilla!

Alas, he's cured in the next issue:

Demon Transformation Round-up (Demon Transformation)

Daymon here is a round of demon transformation courtesy of Ian Rickey. The first transformation is from a dream scene in The Disturbance:



The next is from Conton (獣神伝説; Jûshin Densetsu) where a boy transforms into a kaiju from his nightmare:


The final video for the round up is Black Past, where Thommy (Olaf Ittenbach) transforms into a demon after being possessed by it: