Ladder-Mouth: Evidently the gods thought trolls and ogres weren't sufficiently dangerous. A twenty foot or more tall hairless troll-like figure with a short tail and an odd, splayed arrangement on it's limbs. Ladder-mouths get their name because their mouth splits their head vertically, with inter-meshing pointed teeth and no lips. Each side of the head has one eye, ear, and nostril. Ladder-mouths are fast, strong, sturdy enough to ignore unenhanced attacks using mundane weapons, and regenerate quickly, including missing body parts. Thankfully, they are at best of animal intelligence. The brain is somewhere between their shoulders.
Langolier: The piranha of the “lethal ball” class of monsters. A flying pac-man with tri-lateral symmetry, no eyes, and an insatiable appetite. Where the food goes is unclear, but some arcanologists believe langoliers are parts of a much larger monster, either in another plane, or simply disconnected by a form of spatial magic.
Latex Fiend: In contrast to the Langolier, the weakest of the “lethal ball” class of monsters. Fundamentally a pissed off kickball with a mean face and jagged seeming teeth. A moderate threat to pre-adolescent children, and sturdy enough to require weapons sharper than a pointy stick.
Libellula: A man-sized dragonfly with the ability to fire barbed darts out of the underside of its abdomen. Native to both coastal and inland wetlands, libellula have been encountered as far north as the Anyube River region.
Lich: The general category of sentient undead who have achieved their state deliberately and voluntarily. While a large fraction of the Lich population fit the classic “magic user engaged in occult rites to extend their existence”, vampiric thralls and lunatic owners of divine artifacts who have surgically removed important organs also fit the description.
Ligarex: A type of giant freshwater leech, generally around thirty feet in length. Covered in a nearly frictionless mucous, they are highly resistant to crushing and slashing attacks. Stabbing one is a good way to get the beast to generate an electrical shock, which it can do over an area in water. Delicious when roasted.
Lizard, Metal: A reptile about the same size and build as a greater salamander, frequently found on the fringes of dwarven territories. The metal composition of their armor plates is determined by their diet: young ones usually haunt tailing pits. Not fire producing, but frequently venomous. Dwarves, and miners of most races, despise them: the trouble is how to kill one without bringing the mine down upon your head.
Lorenz Lamia: Similar in appearance to a naga, but with a human upper body and four arms. These immortal creatures are universally female, reside in ancient Divine Era ruins covered with runic inscriptions, wield a unique form of mathematics-based magic, and are quite insane. Survivors describe them as caught up in some great work in which they hope to turn back time and prevent (or cause) some great calamity in the past. There have been a few reports of even scarier two-headed representatives of the species.
Luray: A giant land dwelling eel, native to caves and tunnels. Territorial, mean, and equipped with a mouth full of pointy teeth.