Great artwork and clean keys with some fun enemy stat blocks.
One thing that might benefit from expansion, and that is what water it is that Cerdita wants to cross. It is quite different if she just wants to get over the river, or if she wants to get off the island entirely (because of the effect she can grant), and having the author’s intent be clearer here might be good. (Also, minor typo here: “possess”, not “posess”.)
This one is a little lighter on the science side of things than most of the other submissions, but it can still be pushed fairly easily in that direction with some more labs and weird chemicals and such.
I think that the biggest thing missing is how to achieve the overall goal for hook #2, given the lack of things to use to escape the island properly in the keys. The other two would have the PCs arriving at the island with a ship to use to get away afterwards and are much stronger motivations in general, I think. (I might still do something slightly different with Camilla, but overall that hook works for me.)
Definitely easily runnable though, nice work.