<h1>PRIMERA PLANTA: LA TUMBA FALSA</h1>
HD is decided based on size and mass of the monster (This is the Attack Bonus the enemy has to their attack, to get Hit Points either roll a number of D8s equal to the HD, multiply HD by 4.. or multiply by 5 if you're mean)
DMG is dictated by how lethal their weapon is
AC is dictated by how strong their armour is
Movement, morale, number appearing and other classic D&D stats can be decided on the fly based on logic because OSR tends to ignore/abstract them
HD samples (or just use PC level as reference):
HD 1/2 is a kobold
HD 1 is a goblin, hobgoblin or orc
HD 2 is a ghoul or gnoll
HD 3 is a hippogriff, gargoyle or bugbear
HD 4 is a centaur, werewolf or ogre
HD 5 is a small hydra
HD 8 is a hill giant
HD 10 is a black dragon
HD 15 is a storm giant
DMG samples (or just use weapon damage as reference):
1D4 is a lions claw
1D6 is a bear's bite
1D8 is an owlbear claw
1D10 is an ogres' club
Hit by dragon's breath? Suffer damage equal to the dragon's current HP
AC samples (or just use armour stats as reference):*
10 is unarmored
12 is leather or thick hide
14 is chain or a tough carapace
16 is plate or near impenetrable dragon scales
You can +1 or -1 too if the monster is particularly quick or slow (zombies I'd drop the defense due to their slow reaction times, blink dogs I'd increase their defense due to their inhuman speed)
CREATE A COOL SPECIAL ABILITY:
Regenerating limbs
Paralysing shriek
Can absorb people
Can grab people with their tongue
Can only be harmed with silver
Is invulnerable unless you speak their true-name