I'd agree with the possibility of it hatching Mutants. It won't overshadow the Fallen Elf/Druid (repeated applications of that effect from one source) or the spell Mutation (unpreventable/lobotomizable, also usable in mono-entropy). It's fine for the effect to remain
instead of
. Any card which has absolutely no use in any form of competitive environment does not contribute to that environment, and therefore might as well not exist.
"Fun" decks can come in a billion flavors, and a billion themes. You don't design cards for "fun" decks - theme decks can pop up anywhere, and always will. You want cards to have a specific, meaningful choice attached to them - even if it's a choice many players reject - for competitive play.
This one, right now, clearly does not.