[quote=@Lugia]
You mentioned his character by name. That, at least to me implies that your character somehow knows him.
[/quote]

It's written in a third-person perspective. This doesn't imply that the character knows the other character, it implies that the narrator knows the other character. Either way, it's generally easier on both the writer and the readers to just refer to him as "Dexter" than "The Growlithe" or something all the time.