Four short lines, and a whole odd little philosophy. The speaker claims to have once been a dog, and that past life has left its mark. Now the speaker sleeps "in Greek," a funny, puzzling phrase that might suggest dreams in an ancient language, or simply a sleep that feels old, deep, and a bit mythic. Then comes the creed: "I believe in / supper, not work." It borrows the solemn sound of a religious statement and uses it for something wonderfully simple.
The title, "Legacy," makes the joke richer. What gets passed down isn't money or wisdom but a dog's priorities: rest, food, and a lack of interest in toil. The speaker seems content, even a little smug about it.
The mood is playful and dry, with a lazy warmth. The poem's humor comes from mixing the lofty (Greek, belief, inheritance) with the humble (naps and dinner), and it leaves you smiling at how sensible that might be.