There was a custom fight on an EMU server I played called "The Forestgloom".
The event was supposed to go like this:
You "climb up" the aqueduct in Trakanon's Teeth. Once you are on top of the aqueduct, you fight your way through slimes to the end. Along the way you dodge some mechanics (black slimes rolling down the path you need to avoid). Once you reach the end you engage The Forestgloom. Or, you're supposed to.
There is a timer for the fight. Once you begin (climb the aqueduct) you have a finite amount of time to engage the boss. If you don't make it, you are pushed off the platform by black slime and water, resetting the event and making you start all over. Just before engaging the boss, however, my guild at the time told me (and anyone else new) to wait for the emote that indicated everyone would be washed down the aqueduct and the encounter was reset. I suppose where we were sitting was a weird goldilocks area that didn't actually function properly, because we both: didn't get washed away AND the mechanics were stopped.
I learned after a wave of punishments happened that when you engage The Forestgloom there are a lot of mechanics you are supposed to watch for. The left and right side of the aqueduct get electrified, when one side does you have to move to the other side otherwise you'll instantly die. While moving from the left to the right side you also have to dodge slimes that roll down the aqueduct. If you get hit it takes roughly 75% of your max health. During one phase there is a solid wall of slimes down the center of the aqueduct, and a tank or tanky melee needs to purposely run into a slime to break the solid wall for healers and casters to cross from one side to the other before lightning kills them. While doing all this you are supposed to be healing, DPSing the boss, and making sure you don't accidently walk off the edge.
My guild at the time would wait just before The Forestgloom until the emote happened, then engage. This stripped all mechanics of the fight away EXCEPT the lightning. So an almost top tier fight was reduced to walking from left side of aqueduct to the right side, or vice versa. I knew something had to be off about it, but I figured this fight had been on farm for so long it was all fine.
I learned it was all an exploit when we got our Forestgloom gear taken away during a raid, when the staff learned about it.
Once I learned the REAL way to do the fight it felt more engaging and fun, but essentially getting free top tier gear was pretty funny at the time.
[EDIT]
Also while everything else is going on during the fight wisps spawn that the tank has to pick up and DPS burn them down, before reengaging the boss. If ignored they stack up and essentially cause a wipe.