|Bob the Goldfish|
He was a pet belonging to Cody Bennett.
When Bob died, Cody stood by Dexter Morgan as he solemnly dropped the fish into a toilet, after which it was flushed. Cody then remarked on wanting a "snail" now, before running off to eat breakfast.
Dexter reflected on the fact that he had sent many to a watery grave. At that moment, the fish floated back into the toilet bowl. That symbolized a later part of the episode when Valerie Castillo, a victim, reappeared in the exact spot where Dexter had killed her. Dexter was mystified because he had dumped her body in Bay Harbor. He flushed the fish again and, later, dealt with evidence that could link him to Valerie's murder.