Yeah, it's a riff on the old random factoid you used to see all the time in papers and books where someone would be talking about something like Spanish Rice and the editor would helpfully point out that in Spain they just call the dish Rice. Also, it's just fun to make puns sometimes.
A similar joke:
Batman and Robin are in hot pursuit of the Joker when they hop in the Batmobile. Unfortunately it fails to start so Batman tells Robin that he is going pull out the Batskates and continue to chase the Joker. In the meantime he tells Robin to check the battery. Robin agrees but after a moment pauses to ask "What's a 'Tery'?"
A similar joke:
Batman and Robin are in hot pursuit of the Joker when they hop in the Batmobile. Unfortunately it fails to start so Batman tells Robin that he is going pull out the Batskates and continue to chase the Joker. In the meantime he tells Robin to check the battery. Robin agrees but after a moment pauses to ask "What's a 'Tery'?"