I used to enjoy going to Redridge on my 60-70 Orc hunter, taming Bellygrub, naming it Bellygrub. Then place it where Bellygrub patrols while hiding behind the nearby tree using Eyes of the Beast (controlling the pet) and slow walking “Bellygrub” back and forth as NPC-like as possible until some lowbie Alliance dog came along with the Bellygrub quest and not so much situational awareness. Meanest level 24 boar they ever fought!
Quite funny!
I leveled my priest from 30-50 during the first Korrak’s Revenge. A good chunk of it I spent in a single BG, of which I spent 90% of the time just mind controlling the same hordie boomkin off a bridge. At some point I have to imagine they were also having fun.
I remember you!!! j/k but I have fell victim to that before, off cliffs I went!
When “Have group, will travel” was a thing, Summoning the Raid group to the Highest point on SW Cathedral, but I’m not a real troll, I cast slowfall on every single raid member as they “zoned in”.
I’ve yet to catch someone with a portal to ancient Dalaran, but have fell prey to it at least 3 times in the last few years. Every time I let the mage know that he indeed got me and that I found it hilarious. Because it is.
Tricks of the trade on healers during the first introduction of LFG.
Posting “if Trump was the Lich King” topics in the forums and watching people go nuclear.
Castingslow fall on people in battlegrounds and watching them glide around and sometimes over the edge of stuff after not noticing.
two stories, both from when I played a rogue waaaaaaaaaaay back in around TBC era.
I always played NE rogues, so getting swords trained was a pain back then. the most fun route i ever took ended up in mean sneaking on the ogrimar zepplin and then jumping off when it zoned in over westfall.
the other is when i foudn that that while ganking is fun, what is Way more fun is just stalkign somebody in stealth, waiting for them to hear the stealth detection noise before retreating. I would basically wait until they were int he middle of combat before i would stealth in front of them to the point that they would see me and then walk away. reactions were priceless.
Ok, this may or may not be a long one.
Back in 2008, I used to watch my hubby play WoW, eventually I decided I would like to try it.
I created a character on his account and I’d quest, and collect loot etc, I eventually got to Northrend and my hubby had a grand idea of getting me to Sons of Hodir to quest up there.
He logged onto his dads account, a DK, and we grouped up, he
used Gorefiend’s Grasp many many many times to get me up that mountain, lots of failed attempts etc eventually he got me to the top, only to discover … nothing there, no quests, no storyline, nothing, because I was phased … we still laugh about that now. Fun times.
Murdering known quest givers for hours on end all day long in key cities. Never any players. Just their quests.
That’s some evil genius level of trolling. I approve 
When i play a priest with my friend, i set him to focus.
I wait until i see his cooldowns popped and then life grip him as far away as possible from the boss.
It is hilarious.
Why did they go nuclear?
He would be dead. That’s a good thing.
Celebrations would be in order.
Oh back in Cata I was the 14th ranked dk on the server and our main tank was the 13th (bat rasterd was just ahead of me by like 1 ilvl).
We used to queue for random dungeons, and this was completely toxic, completely naked. We would pull everything and die pretty quick. We would then blame the healer and kick them.
Once they were gone wed put our gear on and solo the dungeon for anyone who stayed.
It was mean spirited and cruel to healers but man it made us laugh back in the day…
Ah yes! My first character ever in 2005 was a Rogue! Many “tricks of the trade” were deployed before that became a thing. While stalk-ganking a like-leveled person (revenge for them corpse camping me when I was 10-20 levels below them before) and they called in their +10-20 level babysitter friend. Sap the friend, murder the person anyway, then move away, turn hard right as you press stealth (best Scottish accent: "let them see you do it), then immediately turn back left to throw the larger pursuer who is just coming out of Sap and surely itching to get to you off. You could not have them get even close to you or they see through the stealth! Hilarious standing on a hilltop nearby watching them run grid patterns looking for you 
wait 2-3 minutes, repeat.
I had /dance on macro incase somebody came to gank me, on some rare occasions they would dance as well. gouge, sprint, stealth, turnabout on the direction you were running and escape.
I’m going to miss committing murder-suicides with the slime toy in SL zones.
casting fort on people jumping from the zepplin only to find that now their current health was far enough under their new max health for them to die by the percentage fall damage
Many years ago. Wall jumping was a thing. And you could hide in the flag rooms in WSG. Forcing the match to go on and on an on. This was before they put timers in. Going into AV with a PVE geared group, and wall jumping, or mt. jumping, and killing Vann before any towers were touched. “Creative use of game mechanics” or guess it’d be creative use of game terrain 