Croagunk shared a very feirce rivalry with Saturn's Toxicroak which started the moment they first saw each other. It is unknown exactly why Croagunk hated Toxicroak so much but it's rivalry with its evolved form was so strong that it would often ignore Brock's advances on women. Croagunk was once seriously injured by Toxicroak who smashed him through a skylight and then stabbed him in the stomach with one of its claws. Croagunk eventually got his revenge during his final encounter with Toxicroak, smashing a Brick Break onto his evolved forms head and defeating it, ending their rivalry. Some people say that Croagunk has a crush on Cynthia
