RIP

Scheduling issues usually becomes an NPC in my group lol
- My groups usually think of them as a powerful fey creature who sometimes just whisks people away for an indeterminate amount of time, only to bring them back later.

Jokes on you, my Undead Warlock was already dead to begin with.
- If you're an undead necromancer, can you re-animate yourself?
  
  There are no mechanics for that, but my DM so cool that he would've allowed it :D
- It is like flammable and inflammable then?

Player character deaths in my games so far:
Beheaded at the bottom of the ocean (he got better)
Crashed into by a banshee powered aircraft
Touched a god killing weapon which is too full of sadness for mortals to handle
Does converted to an NPC upon leaving the campaign for scheduling reasons count as death by scheduling reasons? The character lives on

You can still give them a heroic death in the narration
- Or an amusing one.
  Way back in high school, we had a massive Mage campaign. Someone brought their asshole boyfriend who was a dick from the beginning by insisting that no, he wouldn't play a mage. This was World of Darkness and he was going to be a vampire. And he kept being a dick for a few more sessions. Then they broke up, so the DM had his character sucked into an air vent and mushed into a pulp by the razor sharp extraction fans while we were walking down a corridor. And we all moved on like it never happened.
  
  Bonus points if the death could have been easily avoided, had the character been a mage.

I just had my halfling bard/rogue die from a fist bump.
Homebrew ofc, but one character got gauntlets that on hit had a 1% chance for insta-kill (percentile die). Upon entering boss fight they fist bump my character and the DM tells him to roll. Gets a MF 100 and turns my Lil guy to ash. It was amazing and hilarious.