The Nacreous Outcast
From The Fifth City Wiki
"It drips eagerly. Perhaps if it comes to your cabin you should put down some sort of matting."

The Nacreous Outcast was abandoned in Port Cecil to be a slave to the Principles of Coral because its views opposed those of its fellow Rubbery Men. Given that it can speak English, it can be inferred that it loved a human. (The thought!)