Whenever Goblin Psychopath attacks or blocks, flip a coin. If you lose the flip, the next time it would deal combat damage this turn, it deals that damage to you instead.
The destruction he causes is nothing next to the chaos in his mind.
The ability triggers when it attacks or block and resolves before combat damage is assigned. This gives you a chance to possibly get rid of it before it hurts you.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.