In every game we play now, we always have a random NPC called Billy-Jack based on a guy our group knows. The character has the lowest intelligence score and a fairly high strength. Every mission we end up sending him on a suicide run or leaving him to fend off a horde of angry crystal spiders while our group runs off to have a tea party. It's a staple in every game that we have to find a way to have our Billy-Jack die off before the night ends.
Also remembering back to my very first game of D&D. A few friends and I were playing a simple game, just goofing off and having fun. The GM decided to send a Gelatinous cube our way, blocking us from going further into a dungeon. I asked "What's a Gelatinous cube?" GM explains to me that it's a giant wall of Jell-o that waits for people to fall into it so it can eat them. So I figured that all it wanted was something to eat and it'd go away. So my Dwarf grabs the nearest halfling and hurls him in. Fun times.
I also made a little mascot for our group based on that and a sad emo kid, I called it the Big Pile of Vampire.
"Snooki gives birth to Heavy Gun Drone squad, someone says they are over powered, then the world ends."