I believe that shapeshifting will certainly be possible (just change the model type and animations). However, how will you remove items and clothing? Can I shapeshift into a sheep or a chicken, lol?

Also, I'd come up with a list of possible art assets to select possible shapeshifting animals or creatures from. No sense doing a cat if there is no cat asset (unless it's a placeholder).

I'd start with tank (bear), offense (wolf), and magic (shrill or something) and go from there.

Best of luck to you!

After playing the game a bit and having fun killing the creatures, perhaps as a "speed" form you could have a Air elemental, but if that is to humanoid, you could have some form of cat creature, perhaps the "Speed" form would have 1/3 of the attk and 1/2 of the def, but 2x the combat speed, and movement speed, this could come in handy for moving around quickly, for your druids, and maybe if you find suit someday, adding a swimming form, so the druids can travel across the seas without the help of a boat, would be interesting to see a dolphin I dunno if the sea form is possible, or if it is, it would be imbalanced.

Altough, I did notice that def makes it harder to hit someone entirely, since when fighting with decent armor I tend to dodge a lot more then average,

So maybe te speed form would add 0.3 dexterity or something.