Sharklings

The halfling burglar, Oli Snigg, crept along the slick corridors of the Undercity of Chaubed.  He’d purchased a darkvision spell from a wizard and was grateful that he had done so.  So far, Oli had managed to avoid other thieves and adventurers. The few traps he had encountered were old and easily avoided or sprung.  
Oli was just thinking that this job was a little too easy when he spotted the sharklings. They rounded the corner ahead of him, a pack of six monstrosities with dull gray skin and shark-like heads.  The minute they appeared, Oli reached for his daggers and began to slowly back away.
The sharklings all swung their heads toward the halfling.  Their wide, toothy smiles seemed to stretch into infinity.
Then they came at him.

Sharklings are monstrosities created ages ago by a wizard named Loirath the Cruel. He liked to crossbreed different life-forms, using magic to create hybrids.  Sharklings were one of his more successful experiments.  He used them to protect access to his sanctum, allowing them to eat anyone who trespassed.  Ironically, Loirath was fed to his own creation during the Wizardic Pogrom of 1746.
A sharkling has the body of a humanoid and a head resembling a shark’s.  Their skin is a uniform gray and has a rough, grainy texture to it.  Although they have eyes, they have poor physical sight, and rely on their blindsight and a keen sense of smell to navigate their homes and hunt for prey. Their fingers and toes are webbed and they possess gills that allow them to breathe water or air.
Sharklings live in small packs of six to eight. These packs generally consist of one or two females and several males.  Their culture is primitive and violent. Sharklings are hunters who will attack anything their size or smaller.  They will attack the members of other sharkling packs as well as any stray adventurers.  They seldom use weapons, preferring to rely on their bite attacks.
Sharklings are born from eggs. Every year sharkling females lay egg deposits that the males compete to fertilize.  Female sharklings nurse their offspring for a few months, then they are raised communally.  If times are hard, young sharklings are often devoured by their pack.
Sharklings are found almost exclusively in dungeons. They thrive in artificial aquatic environments, but fail to do so in similar, natural environments.  Sharklings encountered in the wild are killed without hesitation.
Goblins hate sharklings and will often go to great lengths to exterminate them.

SHARKLINGS
Medium Monstrosity, Neutral Evil

Attributes
STR 11 DEX 13 (+1) CON 11
INT 05 (-3) WIS 09 (-1) CHA 06 (-2)
AC 11 (Natural Armor)
HP 12

Traits
Speed: 30 feet
Skills: Stealth +3
Senses: Blindsight 30 ft., Passive Perception 09
Languages: Sharkling
Amphibious. Sharklings can breath water or air.
Keen Nose. Sharklings have advantage on all Smell (Wisdom) checks.
Pack tactics. Sharklings have advantage on attack rolls against a creature if at least one of the sharkling’s allies is within 5 feet of the creature and the ally isn’t incapacitated.

Actions
Bite. Melee Weapon attack: +4 to hit, reach 5 ft., one target. On a hit, deals 1d8 piercing damage.