
For those who aren't familiar with the term, a headcanon is essentially an idea or thought about details in the franchise, that could just as well be canon, but are just never mentioned or brought up in the series. A headcanon can also be an expansion of an already mentioned or suggested fact. An example would be: "I think that Puar and Chiaotzu get along with each other, and consider each other friends." or "Yamcha secretly collects action figures".
Here are some of my own:
-Saiyan hair is essentially fur, as it doesn't grow from the day they're born, and sometimes fluffs out (the only instance where this happens is after Goku has blasted Vegeta over the clouds after the beam struggle, and Vegeta starts getting real temperamental, and both his tail fur and hair kinda fluff out. I know it's mostly for comic relief, but it's still interesting enough for me to include it)
-Fusions have a unified voice in-universe, while we only hear the two voices on top of each other.
-As Saiyans are mainly carnivorous, they have short, albeit sharp canines even when not in their Oozaru form.
Post whatever you like here!