Canyon Viper (5e Creature)
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Medium beast, unaligned
Infrared. The canyon viper can sense the heat signatures of all creatures within a 30 foot radius not behind at least 5 feet of cover, even if they are magically hidden.
Bite. Melee Weapon Attack: +6 to hit, reach 9 ft., one target. Hit: 7 (1d6 + 4) piercing damage plus 10 (3d6) poison damage. The target must make a DC 12 Constitution saving throw, taking the poison damage on a failed save, or half as much damage on a successful one.
The larger and fiercer cousin to the pit viper, canyon vipers are ambush hunters who lie in wait for their prey in chasms and ravines. They prefer to stalk their prey at night, utilizing the loreal pits near their eyes that give them the ability to see heat signatures. Canyon vipers will eat pretty much anything that they can squeeze into their mouths, although they do tend to prefer the eggs of large birds if they're available. They'll live anywhere you can find a large pit, from dense rainforests to the most barren of deserts, even underground if that's where the food is.