But seriously, mutant jellyfish? Yeah, basically. That's a golden jellyfish from Jellyfish Lake on the left. It's a subspecies of the spotted jellyfish that reside in other area lakes (on the right) but has become visibly different over time. But what you should really care about is that its stinging cells or nematocytes (thank us when you nail Final Jeopardy tomorrow) have very little power and are, as such, harmless.