The latest trick he's discovered is to tap Satin (the 19-year-old white cat) with his paw. Satin being cranky, this causes her to take a swipe at him. However, Vir has mastered the trick of taking an immediate side-step. Satin being an ancient cat who doesn't see or hear very well, this causes her to miss.
We try to discourage this when we catch him at it. He probably needs a cat closer to his own age to play with, but then they might both pester the older ones.