The jumping spiky is/will be another variation on the Spiky badguy. As usual, it looks like an innocuous spiky until the player gets near it, at which point it spontaneously hops into the air, hopefully nailing the player.
I modifed the code to get it compile with supertux 0.4.0 now the only problem is that it won't jump. It sees the player, it crouches but don't jump. Advice?