Sousei no Onmyouji
 

Not my strongest area of preference, but I'll share my find. Arm growth of female villian in episode 34 of the this series. It is sustained throughout most of the episode. It is a very small find and I didnt really want to make a whole thread for it, but there isn't a general findings thread here like in some of the other subforums.

http://kissanime.to/Anime/Sousei-no-...-034?id=132548

Re: Sousei no Onmyouji
 

Her legs grew too, and she reverted back and forth a few times, then she grew into a giant monster (same proportions but with jagged teeth)

Re: Sousei no Onmyouji
 

It's a muscle and Giantess growth with multiple muscle sequences focusing on her arms and legs, the giantess transformation happen off-screen. The character has a good design but she dies as the end so we won't see her anymore.