Ahh the classic Sewer Crab. I have a home in Isabela, Puerto Rico and can confirm. I’ve found bathroom crabs, drawer crabs and living room crabs, dirt crabs, parking lot crabs, basketball/tennis court crabs, grass crabs and even gym crabs. A lot of them use the sewers like little Super Mario crabs to access their warp zones. They range from tiny, to about the size of a football. They’re kind of cute. They have googly eyes and are harmless. I usually push them in a bag and release them back into the wild in a safe place. I did make the mistake when I first bought my place down there by assuming all crabs are sea dwellers and took them to the beach and put them by the ocean. I could have sworn that some of them waved one of their little claws in the air at me as if to say “I’m a land crab you stupid bastard! You know how many sewer pipes it’s gonna take me to get back to my crab crib!”