YA book 90s shapeshifter boy turns into creature at end

[Reader]

I think it was a YA book. I read it around 20-25 years ago at my school library if I’m remembering correctly.

It was an odd book, not sure if I even enjoyed it, but lately was thinking about it.

It had some sort of Shapeshifter or changeling boy. First he’s a young kid, I think with no memory, and he lives with a family and has a sister.

He eventually gets in some sort of trouble and then he runs away? Later he pops up in a lake as an older boy and is found by two kids and he gets taken in by a teacher I think and integrates himself into this community.

I’m the end, he turns into a creature, mates with a cow or horse or something that’s in heat and then runs off when caught?

It was a really strange book, but it’s bugging me

[Becca]

It might be the same book that Lee is looking for here - https://www.goodreads.com/topic/show/...

They remember the sex with a horse / cow, as well the protagonist using peyote buttons to suppress his shapeshifting / inner beast - so those extra details might help. Lee mentions The Book of the Beast series by Robert Stallman (first book in the series is The Orphan: The First Book of the Beast) being close but not quite right.

[Reader]

I don’t remember peyote buttons, but otherwise it’s spot on.