The Mighty Thor (Caveman/Neanderthal Transformation)

Thanks to Ogrebear for finding issue 231, pubished in 1975. A seance gone wrong when one of the attendees is possessed by and transformed into a Neanderthal who calls himself "Armak, the First Man."

Alas, Armak gets defeated:

The Incredible Hulk (Ape and Neanderthal Transformations)

Thanks to Ogrebear for recommending issue 266. The Hulk (aka Bruce Banner) is riding along with his friends Rick Jones and Betty Ross when they come across some extinct apes...

The Hulk finds out that the High Evolutionary has been busy devolving people in the area. The first victims were the apes our heroes encountered earlier, who were formerly soldiers: 

The villain then evolves Rick and Betty into Neanderthals:

Primal (Muscle Growth)

This is co-editor Kumaguma, bringing you a transformation from the new Gendy Tartakovsky cartoon Primal, discovered by  Musclelover on our blog's Discord server. In the fifth episode, Spear the caveman and the tyrannosaurus Fang are captured by apes and made to fight with warriors in an arena. The shaman that surveys the combat gives the apes a drop of a potion that increases their muscles and aggression. Spear manages to free himself and drink the entire potion, hulking out against his captors:

Art Round-Up (Bear, Boar, Dragon, Hippopotamus, Monkey, Neanderthal, Orc, Tanuki, Werewolf, Shark, Muscle Growth, Age Progression, and Weight Gain,)

Note from Apuleius:
The majority of this post is Daymon's hard work, but before I hand it over to my hard-working colleague, here are some pieces I've found online...

* A raccoon dog sequence by @iDuSkFeRiRoC, inspired by a scene from the Kitaro anime.

* A kid-into-werewolf sequence by @YojoooHan.

* A fat cat sequence with plenty of weight gain by @CatLewder--and from the same artist, a NSFW deer TF.

* A "bulk" transformation from the webcomic League of Super Redundant Heroes. That burglar doesn't know a good thing when he sees it!

* I received the following note from a reader named Lamarcodon:
"hi guys, I just finished a comic that has one of my characters going through a few different 'getting bigger' changes-- taller, muscles, fat, just LARGER in general (I even tried to 'draw' his voice getting deeper as he grows). Here's a link to the first page, and the rest should have "next page" links to click on.

***

On to part two of this post--here's Daymon!

The first artist specializes in muscle growth, weight gain, and transformation into different fictional characters--he is called Futobara.  You will need an account on DeviantArt account to view the work.
The first section is Sequences, filled with different comics with various transformations.
The next is Sketchy, which consist of sketches.
The final section is Futobara's Tales of Transformation, comics with their own stories.
He also has an alternate account called Futobeans, containing GIFs based on transformative drinks or the like. Here are the cards for your pleasure:
Ample Stout
Baby Guinness
Bacon Sour
Beast Daddy
Mighty Brawn
Paleolithic
Reimhraich
Swiss Cop Costume
Random Switch
Here are the sequence versions of some of them: https://futobeans.deviantart.com/gallery/65997448/Sequence-Versions

The next artist is Kerun, mentioned by Wrightguy0 on our Discord channel, who is known for his transformation commissions. Here are some NSFW sequences (a FurAffinity account is needed to view them):
Bigger and Hairier
Tf Drive-Full Sequence
Tasty Noodle
Pesky Leaf

The next artist is izayoi_16 , who specializes in manly transformations and was mentioned in the last update. Some of his work shows age progression as well. Here is the list of his NSFW sequence (FA account needed to view):
boy 2 bear
a nightmare
tanuki leaf
Age progression & transformation
Shower time
AP-TF-MG-WG (sequence)
AP-TF-MG-WG (pages)
Orc Transformation doodle
Becoming the Wolf
A link to his Pixv art gallery (Pixv account needed to view): https://www.pixiv.net/member_illust.php?mode=medium&illust_id=66371743

The next artist is bear-tf-polar, who draws muscled and rotund characters. This artist was suggested by CourageWoof on our Discord channel. A list of his works (FA account needed for NSFW pieces):
Bowser tf sequence (NSFW) 
Shark tf 1,2, Captain Shark , Reference(NSFW) 
Werewolf daddy tf-ing (NSFW)
Werewolf tf art pratice 

The final spotlighted artist is Volkenfox,who draws lots of muscle growth and weight gain. Most of his work is NSFW, so you will need an FA account to view. Here is a list of his work:
Transformation Commission:draco135
Fitting the Job Application
Commission:Ryanr
Welcome to Dogwood
FREE Public Sequence Round #2
A Gifted Sword (Comic)
A Gifted Sword (Sequence)
Commission: Rekzar (Comic)
Commission: Rekzar (Sequence)
Commission: Theowinters (Comic)
Commission: Theowinters Series
Commission: Type 2
Update Installing!
FREE Public Sequence Series 3
Drinking down a Diety
Commission: Mirokuj7
Rising Earth (Comic)
Rising Earth (Sequence)
Bearing A Manly Burden (Comic)
Bearing A Manly Burden (Sequence)
Winter Weight

If you like his art then I would like to recommend the transformation visual novel Pirate's Fate, available on Steam. Here is a trailer:




And now two werewolfy artworks to send you on your way...

A twitter post of a comic using the character Scott Howl from Monster Prom (recommended by Vanzilen on Discord):  https://twitter.com/Viiperfish/status/996474258594426882

And another recommendation from Vanzilen, an animation by Lei Gong: https://www.artstation.com/artwork/mGG0Y

The Real Adventures of Jonny Quest (Evolutionary Transformation)

By Daymon 

In episode 21 of The Real Adventures of Jonny Quest an alien evolves an ape to a more human form:


The Real Adventures of Jonny Quest - 1x21 (21... by Yu-Gi-Oh-the-offical