Rick and Morty/YMMV

Fridge Horror: multiple.
 * What happened in "Froopy Land" in "The ABCs of Beth". The horror.
 * Jessica and Morty's off-screen extended family are as well as the entire human population of the Earth.
 * What is buried in the Sanchez's garden.
 * Selective breeding of dogs from a dog's (Snuffles) perspective.