On the Spontaneous Generation of Monsters
Left unchecked and exposed to night-air, shite will generate foul and monstrous things. [Sewage left under starlight has a 25% chance per hour of generating one monster per gallon. Landslides, floods, and earthquakes can open up municipal and rural latrines making bad situations terrible.] Called by some accounts goblins or kobolds or cess-trolls [a more general term], these small noisome creatures usually have little more than animal intelligence. Frighteningly enough, these abominations can breed themselves from their own droppings. [Only 1 out of 10 of these kobolds, gremlins, or whatever-monsters are capable of sexual reproduction. These elite breeders have intellects running the gamut of human potential and typically branch off to form their own tribes.] Often violent in the defense of their territory, cess-trolls can quickly overrun an area. If left unchecked they can deplete the countryside of resources in short order.
Know too, snake eggs grow like a fungus upon the graves of liars. Should a bird make nest above such graves, there is a small chance that each egg lain will grow to an enormous size and produce a fearsome wyvern. [1 in 1,000 chance of 1 wyvern egg per nest.]
Furthermore, bats are born from the screams of lost children rebounding off stones in the wilderness. [Any scream of a sentient being in the night has the possibility of producing a bat. Each successive echo of that scream breeds another bat.] However, should the screams cross a unconsecrated grave thrice, a terrible, bloodthirsty Night Stalker shall be formed from the bones. [AKA a Vampire. The grave doesn't have to be unconsecrated, any unmarked grave will do. The first victim is usually the screamer. Sometimes it's the one causing the screaming, but the world is rarely that just by nature.]
The Dragon is, of course, born of the ashes of the Kingdom falling...
...None know why the many gods have wrought the world this way, but they have. For good or ill, it is our lot to live in it.