Board Thread:General Discussion/@comment-29543192-20161030022827/@comment-29325824-20161030112608

Well, it is said that Mamono reach sexual maturity at age 10 at the latest, but I don't recall it specifying how fast they grow up in general. ...Aside from Slimes who are mature from the moment they are born.

But I doubt it's that fast, considering loli's are a popular thing in the MGE world.