At first I thought he was sort of annoying but I think that's just because Tadashi also programmed him to follow me around. I haven't found anything in his code but it wouldn't surprise me either.

[He's running his fingers through Salty's fur to shake off some of the snow.] I'm pretty sure he spent most of his time making sure I'd stay alive and out of trouble. And now that's Baymax's job. [And since Baymax isn't here, now it's Hiro's job to protect people.]