Molds usually spread quickly and unless you refrigerated the plates will likely
overwhelm the agar surface. Then too, their spores will contaminate everything
in sight. Growing molds and exposing them to air in a lab building is a sure
way of getting your colleagues angry at you.
Now bacteria are a different story.
Alexander Fleming the man who discovered lysozyme and penicillin made bacterial
paintings as a hobby. I have a copy of Andre Maurois' biography of Fleming.
The inside covers, front and back are illustrated with some of Fleming's petri
dish art works. Some are quite complex and detailed.