Probably my favorite transi tomb of all time: Francois I de la Sarra, in the Chapel at La Sarraz (d. 1363), at Vaud in Switzerland. The feasting frogs on face and genitals never fail to freak me out. All those worms are just icing on the cake, so to speak.
Transi tombs were common in the years following the Black Death (c.1346-1353), although they continued well into the 16th century. They reminded viewers of the transitory nature of life and, like depictions of the Three Quick and the Three Dead (below), that “As you are, I once was; as I am, so too will you be.”
EDITED TO ADD: the amazing artist Keren Katz was inspired by this post for the cover of her new comix anthology, available at the Animix Festival: