I've been traveling, and that means there's been a lot of long drives with my kids in the backseat. There's only so long I'm willing to let them watch cartoons on the tablet, because I don't want them cranky or crazy at the end of the drive. So, I gave my son a refresher on Tiny Dungeon 2E, and taught him how to design a quick and dirty five room dungeon.
After hearing some of my stories, he has decided to add his own flavor of gonzo play into the game.
While driving to a family function last Thursday, I created a mighty, axe-wielding warrior-mage, who was sent to save the souls of the dead from a powerful ghoul who was eating both body and spirit alike in a nearby tomb. After defeating the skeletal minions of the ghoul, and avoiding a trap, I discovered a skeletal warrior who still retained some of his mind. I asked the warrior what the ghoul's weakness was. My son replied in a spooky voice: "fabulousness."
I decided to run with it, and had my magician use his magic to clean himself up, wax his moustache, shine his gear, and dye his clothes. I made an entrance in a cloud of sparkling magical smoke. The Ghoul was rendered powerless by my sudden intense style and charisma. As I applied a magical makeover to the creature, it screamed and melted away.
Thus, Haxxus the Bold became Haxxus the Stunning.
In the following days, Haxxus the Stunning resurrected the fallen warrior who advised him, banished dark spirits in the marsh, and slew Takkal, the shadow dragon, sand slowly built an entourage of well-coifed adventurers.
Then he sent me into a swamp cave to defeat a magically warped mosquito. (Both my son and I are allergic to mosquito bites, it seemed like a good monster to him.) I was met at the boundary of the cave by a bevy of zombie orcs and ghouls (the later of which melted due to my incredible charm). The Orcs, however, cut Haxxus, veteran of 8 adventures, down in seconds, leaving me with the band of misfits I had built up (minus the resurrected hero who was left at my tower as a seneschal.)
Then avoided a poisonous mire, before finding a starved and injured dwarf, who informed me that the mosquito beyond could not stand the taste of Dwarf, but is still terrifying.
And damn, it was.
The Mosquito was the size of a horse, and drained a full d6 of life on a successful hit, which it healed. Worse, it was smart, used tactics, and the drone of its wings could animate the corpses, of which its lair was littered. Sonja, the warrior died in the first round, totally drained of her hit points in one shot. My gnomish alchemist, Nibblick, who was our scout and used things like eye irritants and glue bombs fired from a slingshot died in round 2. Thanks to a cruel trick of the dice, Bob, the Lizard-Man ranger died in round 3. Suddenly, Gimlet the Dwarven warrior was all that was left of the party, and the chains, harpoons, glue bombs, eye irritants, and other tricks that we were using to try to take this creature on tactically just fell apart.
While it would not eat Gimlet, it could raise an army of his fallen companions. Gimlet found himself standing on a stalagmite, surrounded by grasping zombies, desperately firing a jury-rigged bow (in which he was not proficient,) at the Mosquito as he bled from a growing collection of leg wounds.
At the very last moment, one more zombie claw from death, a finally brought the mosquito down.
At first, my son, realizing he had unbalanced the encounter and created an death-dealer who could create minions at an alarming rate, considered altering the stats of the monster on the fly. But I told him to roll with it. Sometimes encounters are not balanced. Sometimes instant death is a thing, and sometimes, the dice turn what should be livable wounds into mortal blows... even three rounds in a row.
I loved his ideas of a blood-hungry mutated mosquito that dealt death, and thought I would stat it here for OSR use... although now my wife is wondering where the hell the kid gets his ideas.
AC 5 
ATT proboscis (2d8 + blood drain)
ThAC0 12 [+7]
MV 120' (40'), climb 60' (20'), fly 150' (50')
SV D 6 W 7 P 8 B 8 S 10
NA 1 + 2d4 skeletons (1)
This horror is created by exposure to corrupting magic and the blood of the Undead. It is the size of a camel, although it weighs about as much as a halflimg. It is pale, and it's legs are caked in fungus. It has a dim, malevolent intelligence and understands the language of Demons.
Animating Drone: A Necromantic Mosquito may drone its wings to animate corpses 1d3 corpses as zombies or skeletons up to 60' away, which are under the Mosquito's control. It has no upper limit to the number of Undead it can control.
Blood Drain: When a Necromantic Mosquito hits a living being that has blood with its proboscis it deals an additional 2d4 damage and regains lost hit points equal to the damage done. If a Necromantic Mosquito drains 50hp in this manner in a single day it loses the ability to fly for 12 hours, having become too bloated to fly.
Dwarf Aversion: Necromantic Mosquitos will not attack Dwarves. If Dwarves are present, it will order Undead minions to attack Dwarves first.