Sid is an important character in Flushed Away. He is a sewer rat who arrives in Kensington out of the drain and disappoints Roddy when he decides to stay. After Roddy fails to trick Sid into flushing him back into the sewer, Sid flushes Roddy down instead. When Roddy returns to his home with Rita he tries to pass Sid off as his brother but it is revealed that Sid and Rita know each other. Later, whilst watching the World Cup, Roddy realizes The Toad's plan to drown the rats during halftime so he has Sid flush him down the toilet again but not before letting him take his place at the house. Sid is last seen at the house when Roddy's owner Tabitha arrives home from her holidays with a cat much to Sid's horror.
Sid appears to have lived in the sewers his whole life, though its possible he was a pet on the surface world before winding up in the sewers. Nonetheless, he tells Roddy how he was in the pub when a burst water main shoots him up the pipes to Kensington,and happening to shoot through the kitchen sink in Roddy's house. He immediately starts to trash the home and declares the place his, forcing Roddy to be his butler (possibly because of the suit Roddy was wearing). He goes as far as to push Roddy into the toilet and flush him, although Roddy was planning to do the same to Sid. It doesn't take long before Sid has trashed the home.
Sid at first comes off as brash and rude, but shows some of the same lonely signs as Roddy, mainly interacting with Tabitha's dolls as if they're real. However, Sid seems to enjoy being alone, as he makes no plans to return to his life in the sewer. When he thinks Roddy is going to flush him, he pleads and says he's gone soft, showing a new side to him. Roddy asks Sid to be good to Tabitha, the human girl who cares for Roddy, and Sid promises he will be "as good as gold" to her and he will be the best pet ever. He first treats Roddy like a butler, but by the end the two appear to set aside their differences and become friends.
Sid is a light brown rat that has dark brown hair. He wears a black leather jacket and denim jeans that are too small for him.
- Its possible Sid was the rat Rita's mother mentioned earlier in the film. She says she once met one of Roddy's kind (an "up top" pet) who belonged to an old lady, implying the rat was flushed or ran away to the sewers once the old lady died (as she said "used to be some old lady's pet). Rita's mother mentions how lonely the rat was as he had nobody to talk to-Sid also interacts with the dolls much like Roddy did. He also seems to know a lot of surface things, such as their food, television, toilets, etc. When Roddy returns to the surface and introduces him as "Rupert", his brother, its shown that Sid and Rita know one another.
- He also knows what a cat is as seen at the end of the film and has a fear of them. Its possible its all instinct.
- Its possible all the things he seems to know about on the surface he's seen in the sewers, but he doesn't seem at all scared of the top world nor does he seem to want to go back.