What Is It? Why?
Badger Cereal is the phandom term for the idea of a family/father/son/mentor relationship between Danny Feton and Vlad Masters. The name comes from their nicknames/taunts for eachother- 'Little badger' and 'fruit loop'. The relatonship is often inspired by Vlad's canon want to see Danny as his son (as he wants to marry Danny's mom) and his attempts to connect with Danny or force him into a father/son or mentorship like role (when he's not fucking with Danny's life for fun). There's also thefact that they're the only two half ghosts in the world and with many more years of experience being a halfa, there's a lot Vlad can teach Danny about his powers.
some popular tropes in Badger Cereal fanfictions and fanart are Vlad adopting danny after his parents deaths, vald being an uncle or mentorfigure to danny in AU's where he's good guy/not known to be a bad guy, vlad and danny sparring/vlad teaching danny more about his powers, and Vlad taking in Danny after hisp arents find out about his powers.
Badger Cereal shouldn't be mistaken for Pompous Pep, the term for a romantic relationship between Vlad and Danny!