When a humanoid sea creature washes up in Terry's bleak life they quickly develop feelings for each other - But can Man love Fish, and will Terry's older criminal brother get his hands on the creature before Terry can decide how he feels?
Many dogs in the town have gone missing as part of the plot, and the missing dogs are discussed in conversation. A dog skull and collar are found on the beach. No dogs are harmed on screen.
Newspaper shows a lot of pictures of pet dogs who've gone missing. You see a dog skull and a collar washed up on the beach. Mention later of a pet pigeon being killed with a phonebook.
Doesn't quite get to that point, but there is intent. Later on the main character's mother is stated to have electrocuted herself on a toy in the arcade (on purpose, it seems to be an electric eel game) but it malfunctioned and actually electrocuted her to death. I don't think this was on purpose but I figured I would add this here just in case.
Autism isn't mentioned but the main character is seen to be a little slow (possibly with learning difficulties) and is abused verbally by his girlfriend and older brother for not understanding things.