Ah yes, I've had fun with poetry too.
Rhyming in languages other than English seems difficult. I asked it for a silly rhyme in Dutch, but it didn't rhyme at all. But if I translate it to English word for word, it does rhyme. So there's something going on there.

I also tried asking it to write in 13th century Flemish, but that didn't work at all. However if I ask it to write in the style of certain medieval Flemish texts, it does! (at least it writes something that looks like middle Dutch)