Children's(?) Book series that detail mythological creatures from different mythologies and details them

[Blue]

I remember reading it in middle school so maybe it wasn't children's but they were wider books that detailed mythological creatures. I remember specifically that there was a Japanese one and a Greek one.

I don't remember the authors name but will probably regonise the cover/title upon seeing it.

It was not the monster encyclopedia! It was specific books for specific mythologies. I.e there was one for Greek monsters with gorons and such, and one for Japanese mythology that had onis, etc.

Any help is appreciated! I would love to read it again.