Have you ever seen a cryptid? Do you think any of them are real?

Do you know sea serpents, giant squid and panda's were once considered cryptids? I've seen a few animals that seem to have either disappeared off the face of the earth or not to have existed at all. I don't know what to think about that.

If it doesn't exist, how could I see it?

Bigfoot/Sasquatch/Yeti almost certainly exist there is enough evidence of things like footprints and hairs from them but they are extremely cautious around humans. Scientists think the species are out closest relatives. Nessie is a curious being, the Scotts around Lock Ness are convinced it is real, but then just the legend drives tourism. I was there one day when it was spotted, but was at the wrong end of the lake.

I've never seen one and I don't believe they exist, but the creature you saw could have been something else entirely. I was going to cite the example of Siamese or conjoined twins, but after searching it out a bit I found they've been throughout history and aren't a result of only the last few centuries. But, if an animal of some type, like the tadpole you saw, if their parent's ate some poisonous item, then I could see where it's progeny might only have one larger eye or be bigger than normal.