reporting ninjas

I was in razorfen kraul as restoration druid and a druid feral needed on the caster head dropped by the rare mob. How can I report him for ninjaing?

If you have screenshots, you can report it by making a support ticket in game. More information about reporting players: http://forum.warmane.com/showthread.php?t=325598

thanks. I tried to look for the post about it but didn't find it :) saved it for the next report I'll make ;)