SOLVED. Kids Fantasy. Mysterious animal appears in a river in main character's hometown. Animal wasn't specified but described as something like large otter/ beaver. A major characters set tripwire cameras to photograph the animal. Read 2000s. Spoilers.

[Brian]

From what I remember one of the major characters transforms into this mysterious animal at the end of the book. The whole book has an eerie feel to it. The cover had an otter/beaver's eye with possibly a camera shutter as the iris (might be misremembering the camera shutter but it was definitely a striking eye). Photography was also a theme that stuck out to me as a major character trait of one of the main characters. Main characters are aged around 10-13. Read in early-mid 2000s. Likely written in late 90s/early 2000s. I think the author was a woman.

My memory of this book is very hazy, I read it when I was a child, but I've made half-hearted attempts to find it over the years. Left an impression on me as a child and I'm interested to see what I'd make of it as an adult. Any help or suggestion is appreciated.

[Rainbowheart]

Pictures in the Dark

[Brian]

That's it! Thanks you very much!

[Rainbowheart]

No prob, glad to help out!