In the show Friends, Phoebe found a dead rat in her soda can. This happened in the episode "The One with the Rat".
In the episode "The One with the Rat", Phoebe discovers the rat in her soda can after drinking some of the soda. She then takes the rat to the vet, where it is revealed that the rat had been dead for at least a week. Phoebe then takes the rat to a pet cemetery and gives it a proper burial.