I worked with a guy that used to call me "bulldog". While I'm sure that bulldogs are wonderful pets, they hardly fall in the category of cute and cuddly. I didn't take it personally, because he called everybody bulldog. But some of those folks got really upset, which was his intention.
I needed information from him on a regular basis and I always made sure that I asked for the same information several times. "I told you that." "I know, but I forgot".
He finally figured out that I was jerking him around. He stopped calling me "Bulldog", and I stopped asking for the same information several times. I never did find out what he was so angry about.