Etymology of "urchin"

“Please sir, can I have some more?”

“Ow! Get away from me, rapscallion, you’re all pokey!”

At least, I’m assuming Dickens didn’t write about youth sporting spikes (imagine if he had - Dickensian Punk!), tube feet, and an Aristotle’s Lantern.

So why are street urchins and sea urchins called the same thing? I get the Hedgehog-Sea Urchin connection from Merriam-Webster, but why street urchins?
Bonus points to anyone who can use “Aristotle’s Lantern” in a pun.

For one stop etymology, try the Online Etymology Dictionary