A slang term for a small penis, along with small testicles, too, in which the twig symbolizes the small penis and the berries symbolize the small testicles.
You will never be able to make babies with your own twig and berries, dude.
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.