I have to say, great job on this! Your style has this really rounded, almost storybook vibe to it that captures a certain sense of whimsy to this kind of TF extremely well. I think the coloring has a lot to do with it, the colored pencil work leaves a bit of graininess that makes it almost look like something out of a dream. The big and bold posing you employ with this character does a lot too; despite this not being animated there's a considerable amount of squash and stretch that makes me fill in the blanks with some super expressive movement. I think this is most exemplified on this page, where the nose kinda pops out. I think some more anticipation and follow-through can work if you're looking to replicate this style, but as is it's quite captivating. Plus, I really enjoy the results! Swordfish like this are definitely some of my favorites in terms of TF, their larger and distinctive looks lend them well to this kind of sequence. Great job all around!

I really like this sequence! I don't think I'd want to be a fish, but a cartoon fish is a different story - especially one as cool looking as a swordfish! I love the toony style/expressions you gave this marlin, it definitely does remind me of the cartoon fish transformations you mentioned. My favorite of those is probably Mr. Limpet - his fish form has a great design, and while the movie's plot is rather absurd, it is quite funny and entertaining too!

Also the final U-Boat chase scene is actually quite thrilling.

That description also sums up Help I'm a Fish.

I should give Mr. Limpet a rewatch some time.. and watch Help I'm A Fish as well!

There's also the animated Herne The Hunter sequence in episode two of the BBC serial of The Box Of Delights, from 1984.

I've read that book. Thought of basing something on it but haven't quite found anything yet.

Now that's a FISH. :D

Mr. Limpet is actually based on a World War II-era book, in which Limpet has a conversation with Hitler who's traveled in a submarine to find the fish that's been causing him so much trouble. (A friend let me read his copy, but apart from Hitler I don't remember much of the story.)

The movie came out when I was a kid; it was a very guilty pleasure to see a movie based on a TF...I loved the in-between phases of Don Knotts human-to-fish TF.

Speaking of in-between TF phases, did you ever notice none of Wart's TFs are actually shown in Sword in the Stone? The bird TF is simply a dissolve, the fish TF happens inside a magic cloud and the squirrel scene begins with Wart already a squirrel.) Disney's best TF scene will always be Lampwick's in Pinocchio.

The book by TH White includes one nicely detailed description as Merlin turns Arthur into a hawk. And there's a somewhat bizarre moment when he turns into an owl by eating a magic mouse.

The Wizard's Duel in the book is sadly not as interesting as it is in the movie. But Arthur has much more personality in the book.

If you think about a lot of the older Disney features, the protagonist is more of a bystander than actually driving the story, which is done by the sidekicks. (The fairies in Sleeping Beauty, the mice in Cinderella & just about all the supporting characters in Snow White and Dumbo.)