TEXT: Lindwyrm 
  Large dragon, unaligned
  Armor Class 15 
  Hit Points 102 (12d10 + 36) 
  Speed 40 ft., Swim 50ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  18 (+4) 16 (+3) 18 (+4)
  9 (-1)
  14 (+2)
  8 (-1)
  Saving Throws Str +7
  Skills Perception +8, Stealth +6 
  Damage Immunities Poison
  Damage Resistances Acid
  Senses Tremorsense 90ft., Darkvision 20ft.  
  (Blind beyond this radius), Passive Perception 18.
  Languages -
  Challenge  8 (3900 xp)
  Amphibious. The wyrm can breathe air and water. 
  Actions 
   
   
   
   
                     
  Multiattack. The lindwyrm makes 3 attacks, one with 
  its bite and two with its claws. 
  Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one 
  creature. Hit: 16 (4d6+4) Piercing + 4 (2d4) Poison 
  damage.
  Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one 
  creature. Hit: 10 (2d6+4) Slashing damage.
  Poison Vapor (Recharge 5-6). The Lindwyrm exhales 
  poison in a 30 ft. cone. Each creature in that area has to 
  make a Constitution saving throw (DC 15). On a failed 
  save they take 22 (6d6+4) Poison damage and become 
  Poisoned for 1 minute. On a successful save they take 
  half as much damage and do not become Poisoned.
  Lindwyrm
  Deep under ground, in damp tunnels and muddy caverns dwell 
  the draconic creatures known as Lindwyrms. These pale, slimy 
  creatures employ their sharp teeth and claws to catch their 
  prey by surprise in the complete darkness of their habitats. 
  Lindwyrms are not as smart as their winged cousins, but they 
  are extremely vicious and territorial. When a lindwyrm is 
  threatened, it will most likely fight to the death in a blind rage 
  of claws and teeth. 
   
  Disgusting lair: A Lindwyrm does not consume their prey 
  fresh. It kills it’s victim and lets it rot for at least a week in 
  its lair. Pools of fetid and acidic water are a place of rest for 
  the Lindwyrm, here they lie in wait and sleep, just below 
  the surface. If anything enters the lindwyrm’s lair, it will 
  attempt to ambush it first. 
  Variant: Spiked Lindwyrm 
  A spiked lindwyrm is a mutated strain of the species 
  in which bonelike spines grow along the length of the 
  body. The lindwyrm has learned to use these to its 
  advantage and can use the following action. 
  Tailslam. Melee Weapon Attack: +7 to hit, reach 
  10 ft., one creature. Hit: 14 (3d8+4) Bludgeoning + 
  6 (2d6) Piercing damage. 
   
  A spiked Lindwyrm can choose to use a Tailslam action 
  as part of their multiattack instead of a Bite attack.
  Bonus Action
  Creature
  
SOURCE: textdata/thevault/Dungeons & Dragons [multi]/5th Edition (5e)/3rd Party/Bonus Action/Creature - Lindwyrm.pdf