Is it normal to torment my ex-friend?

A really good friend met a girl and completely cut me and our other friends out of his life. I went from seeing him every day to not seeing him at all in two years.

For whatever reason, I think it's fun to play weird practical jokes on him. He had no sense of the surreal, so I like to play on this. Once a month, I phone him (from a replacement SIM card) and get a speech synthesiser (which sounds a lot like Stephen Hawking) to quote something at him repeatedly until he hangs up. Last month it was "Make the monkey face, Senor Sock". I don't remember December's, but November's was "You can't be Boris Spassky's happy hat of sushi forever".

I also send him random books through the post. The last was Nancy Reagan's biography which I inscribed with "I yearn for you aimlessly. Love, Nancy". I also sent him a manual on how to fix tractors inscribed "just in case you ever need it".

I also send him emails from a fictional mutual friend I invented and often reference real people we both know but also make things up about them. Our friend Jane recently got a franchise for a pet waxing salon. She does dogs eyebrows and cats underchuffs but she's really hoping to break into goats. Really, though, she does IT work for a registered charity.

I justify this to myself by saying that if he can't be bothered with his friends then he deserves worse than no information about us. He deserves disinformation. Do you think I can justify this or am I just enjoying messing with him?