Q: Can the player with Mal move any Creeper on the table, or does it have to be one they have?

A: We very carefully did NOT specify that it was the player’s own Creepers. After all, there are some Goals which require Creepers, and a player might want to move someone else’s Creeper to themself… or from one player with little chance to win to another who has a potential win condition which would be spoiled by the presence of a Creeper. All of these possibilities are allowed.