Random Wyvern

Originally a specific type of creature from medieval illustrations, this creature has come to often play the role of a 'lesser dragon' in fantasy: a creature which is dragon-like but nowhere as fierce, large or powerful as the 'true dragons'.

Silverwind Nargacuga from Monster Hunter.

On some worlds, wyverns could very well replace true dragons. There are several reasons why this could be the case, such as a more low-powered setting or a desire for more mundane draconic beasts. Now, like many medieval dragons, the etymological roots of wyvern are found in the word 'viper'. That doesn't mean wyverns have to be reptilian or serpentine. The stat block works well for any suitably feral flying beast.

What does it look like?

d12	Appearance
1-2	Reptilian: The Wyvern looks like a lizard or reptile with leathery wings.
3-4	Serpentine: Sineous, this wyvern looks more like a snake with legs and wings.
5-6	Pteranodon: While a fantasy world may not call it a pterodactyl, this is very much what it looks like.
7	Chiropteran: The wyvern looks like a big bat.
8	Dinosauroid: Aside from the wings, it clearly has a dinosaur-like face.
9	Mammalian: It looks like a bear, a cat or a dog but with winged forelegs.
10	Avian: It is feathered and looks like a giant prehistoric bird.
11	Monstrous: Horns, barbed hooks, jagged claws or even tentacles mark this creature as possibly otherworldly. Roll on Eldritch Origin table.
12	Roll twice and combine.

d6	Locomotion
1-3	Standard: No changes from an ordinary wyvern.
4	Big Flyer: This wyvern is more more aerial than land-bound, with enormous wings. Decrease its AC by 1 and land speed by 30’ but it gain +60’ of flight speed.
5	Land Hunter: While capable of being airborne, it prefers to leap and glide than use long-distance flight. Reduce its flight speed by 60’ but improve its AC by 1.
6	Glider: This big wyvern doesn’t fly, merely glide. Reduce it’s flight speed by half. It can’t take off on its own and must drop down from something high. However, it is an expert at killing its prey quick. Increase damage by one size category.

d4	Eldritch Origin
1-2	It is tied to demonic forces. While not a demon itself, it has ancestry in the lower planes.
3	It migrated from the dimension where nightmares come from.
4	Long ago, they descended from a glowing red star in the sky.

How smart is it?

d4	Intelligence
1-2	The wyvern has animal-level intelligence.
3	It is very smart, for a beast anyway. Like a smart chimp or a dolphin.
4	There is an alien intelligence behind those cold eyes. Maybe it knows what words mean, even if it can't speak them?

What special trick does it have?

d6	Special Trick
1-4	Stinger Tail: The wyvern has a spiky which is coated in poison. Functions like the normal wyvern ability.
5	Blunt Tail: This wyvern has a thick, mace-like tail. It lose the poison ability but increase damage from it’s tail by one category.
6	Spit: It can spit for 3d6 damage at a range of 60’. It takes a full round for the spit to recharge.