[Alt Text: A clay Pokémon, Wooper, sits on a table with it's mouth wide open full of pills. Caption by Twitter user at sign Serena Harumi says, "Ambi bought me this Wooper candy holder and the first thing I do is stuff its mouth with estrogen"]
Hello little gay people in my phone! It's a joke, don't store your pills outside of it's intended container. Open air is bad for pills.
I think the closest biological analog is mammals, actually. They can have the ability Thick Fat for example.
I think it's just a coding error that they never fixed between editions (my headcanon is that some employees fought for it to be kept it). They're not called Game Freaky after all.