On my RL birthday. Playing a campaign. I had suffered a level of exhaustion, as the Ranger, staying back to ensure a safe getaway from monsters. As I am making my way back through my favored terrain I am hungry and tired. I spot a birds nest with eggs in a tree. So I climb the tree to get the eggs. Kinda. I fail my climb, fall to the ground, and the sound alarms the bloodhawks who then pecked me to death. (Level 3).

The final boss essentially self destructed because of a trash magic item our DM made (A bell that grants invisibility when rung, you can still hear it) and all of us died except our sorcerer who got NAT 20 and backflipped over the explosion.

So. You ever go to the tavern and drink first before taking a long rest? “I’m not going to get into any fights.” Should be fine?

Ever fallen out of a bar stool after drinking ale in a tavern, and died from fall damage? To be fair I am pretty convinced the DM was tired of the campaign as he bailed on everyone without a word before the next weeks session.

Fighting Medusa in ToA. We manage to maneuver to where we were inside her dome building, now roofless in many spots, after getting mangled by magic storks. Instead of the party collectively readying an action to attack the moment she shows herself(or literally anything at all tactical), other three party members start searching crates and barrels. Medusa slithers in and kills me and another party member, other 2 escape. 

The dumbest way I died was in my first campaign ever. Our group was in a dungeon and our party was about to fight a lizardfolk camp but I was at low health and didn't want to fight so I snuck off into some tunnels next to a river. My character was just chilling, congratulating himself about sneaking off, but I should've seen it coming. One second I was sitting in a tunnel, the next a lizardfolk claw was in my head. 

I almost died on my first dnd session ever because I could't roll high enough to hit a single goblin. He, however, had no such problems. My dm had to bring out a random person to kill it.

Early in my playing career I had a character who was meticulous about being safe.  Belaying ropes, 10' poles, the whole works.  The FIRST time I forget to tie on a safety rope I blew a dex save and fell to my death.  

So, I know that my character almost died (but not completely), but I’m going to write it anyway… My Tabaxi Druid, a wizard Aasimar, a barbarian half-orc and a Kenku rogue, we’re going through a forgotten mine and they encountered a carrion crawler. When the carrion crawler was almost dead and tries to escape, it crawls onto the ceiling and the half orc hits it with a reaction. The Tabaxi hits it with his scimitar and it falls on the party… that was a valuable lesson.

My history with Druids in our campaigns has been tragically short. After three met untimely ends in their early stages, I'd sworn off the class entirely. Below is how my first Druid met his end when he infiltrated a Bullywug compound in a swamp.

Infiltrating their territory required a subtle approach, so I Wild Shaped into a spider, my eight legs carrying me silently through the swampy undergrowth. Just as I was nearing their crude encampment, disaster struck in the form of a DM-rolled random encounter: a single, surprisingly large frog.

Knowing a direct confrontation could alert the Bullywugs to my presence, I engaged the amphibian in what I hoped would be a swift, silent skirmish. Unfortunately, this seemingly innocuous creature proved far more formidable than anticipated. What followed was an unexpectedly epic, albeit miniature, battle. In the end, despite my best efforts, the frog prevailed. My spider form was knocked unconscious, and in a truly ignominious end, I was swallowed whole before I could even revert back. Good times!

skyrim

Somehow, through a campaign that was mostly about tabaxi cults, the party managed to maneuver ourselves into a massive kobold camp. We were all fifth level, but there were hundreds- if not thousands- of kobolds. We promised to join their cult (the cult theme was recurring) if they didn't kill us all, and so we all got our uniforms. Everyone else described themselves as warriors or fighters, and they all received uniforms. I just said I was a cleric & got a "Loser" sign on my head. This came back to haunt us later...

Spent a few days with this cult, proving ourselves. Hid the "Loser" sign as best as I could. But one day, we were having dinner with the warrior kobolds, and the DM decided a gust of wind blew through this building (someone must have left the door open). My cloak hood fell off, and the Loser sign was revealed to the universe. 

This somehow blew our cover (kobolds are always weird). We promised we wished to entertain them before being executed and bought ourselves a few hours. The barbarian in the party got a whole lot of gunpowder, dumped it all over me (I started the problem in the first place), and lit me on fire. 

Boom. 

To make it worse, then the cave collapsed. For the greater good of the party. 

I was a miconid and I got killed by salt when I jumped into saltwater after failing a perception check

Player of mine tried to overthrow a government by sleeping with one of the leaders, promptly got thrown off a cliff by the civilians who saw through his manipulation of what little he got while trying to force himself on the leader.

Was it a bard?

Most likely

to be honest... drowning