As you can find out after reading this, Owen had a great patience while doing his pranks.
So once after a match Owen went to the locker room. Then he went to the back of Gangrel and took his watch out.
He then hid it in his Owen back. The time when Gangrel arrived he looked for it. Of course he didnʻt find it.
Owen wanted to be a good friend and helped him searching for 1 hour.
A few months later, when they were in the same arena Owen put the watch back in Gangrels back.
Gangrel was shocked to see his watch in his back again in the same arena.