Is this supposed to happen?

[Sudeux]

Hey guys, so i randomly found this incubator on my farm one day, is it supposed to randomly appear?

 

[nicodeux]

Hello and welcome to these forums,

This is a special event that happens during night and yes, it appears randomly, like some other items .
You can leave this... incubator... in place or pick it and put it in a chest.

If you don't mind spoilers (which I advice against during your first playthrough), you can get more information here.

 

[Mango Choo-choo]

Yes, it happens.
It is rare but it does happen.
don't be skeptical it is not a bug
it is just because you are quite lucky