I think i'm a little bit of both, As i created my characters, i kind of knew wich one i wanted in the story, but as i've gone through creating Gnarfi, it's appearance and way he behaves was influencing my way to write him and he took somewhat life in my mind as i drawn him more and more, it's like his psyche and behavior was inspired to me by the lines i drew, and he got more precise each time i drawn him.

It's like this for a lot of my characters, i come up with an initial design in my head and visualize them just a little bit at the beginning and then, their own personna bloom / flourish on paper as i draw them, of course there is a lot of imagination involved but, the paper and their body recipient of lines slowly builds their very own personnality at wich point i think i even loose control and i'm driven by their personna / characteristics and they are almost in control of the outcome because i become somewhat fan of them xD or at least, i'm fond of them in some way...

There is a little bit of attachment from some part of your oneself you put in this or that character and you end up liking them equally for very different reasons and it can be because they are the very opposite of another character and the alchemy between them is very funny to write and witness, see evolving.

Very good video by the way. Thanks for sharing this ^^