The Ren & Stimpy Show (1991)

S3E12 Ren's Retirement

Ren is enjoying his 10th birthday when Stimpy suddenly points out that he’s actually 70 in "dog years." This revelation sends Ren into a frenzy as he starts to confront his mortality. He begins drafting a will, plans an elaborate fake funeral, and embarks on a quest to find the ideal coffin for himself.