Incidentally, if you eat the flesh of a strong monster a strong monster will be born.
That is folklore.
It has about as much credibility as gaining immortality from eating the flesh of a mermaid.
If a strong monster could be born like that, then it wouldn't be strange for the people of the Magic Continent who eat the meat of monsters on a daily basis to be stronger.
It doesn't seem to be an ability of monsters to change after eating the meat of monsters either after all.[1]