This plot is in episode 114.

Big Cousin is a character in the "Tom and Jerry" cartoon, appearing in the 114th episode "Cat Concert". In this episode, Cousin is a singing cat who joins a band of mice as the lead singer.

Due to the hostile relationship between cats and mice, Big Cousin is always trying to catch the other members of the band. In the end, in a wonderful concert, the eldest cousin and the band members resolved their conflicts and performed a successful concert together.