I've never forgotten those close-up photos of tadpole mouths that look like a bunch of meaningless black scribbles. Tadpoles have so many weird features.
I thought they were so much cooler than adult frogs when I was a kid, really enamored by these weird slimy heads with tails. I always wished there really could be some permanent tadpoles out there, but the only ones I know of are a rare mutation of African clawed frogs, and they do very poorly.