Swamp Siren Characters

Character design and world design.
The story, in short, is of a siren-like kind of creature in forested wetlands. He's never come across anyone that looks like him except for the occasional human venturing into the wetlands. He befriends a small trio of humans who learn to communicate with him. The siren asks for their help to learn about his origins, perplexed and envious of the community he's witnessed humans have with each other. The four of them travel through the connecting rivers in the wetlands, guided by the siren's dormant powers, and travel through time using the river to learn about how the siren came to be.