Volo's Guide to Monsters
Lizardfolk possess an alien and inscrutable mindset, their desires and thoughts driven by a different set of basic principles than those of warm-blooded creatures. Their dismal swamp homes might lie hundreds of miles from the nearest human settlement, but the gap between their way of thinking and that of the smooth-skins in far greater.
Swimming speed: Lizardfolk have a swimming speed of 30 feet.
Bite: Lizardfolk's fanged maw is a natural weapon, which they can use to make unarmed strikes. If they hit with it, they deal piercing damage equal to 1d6 + Strength modifier, instead of the bludgeoning damage normal for an unarmed strike.
Cunning artisan: As part of a short rest, Lizardfolk can harvest bone and hide from a slain beast, construct, dragon, monstrosity, or plant creature of size Small or larger to create one of the following items: a shield, a club, a javelin, or 1d4 darts or blowgun needles. To use this trait, they need a blade, such as a dagger, or appropriate artisan's tools, such as leatherworker's tools.
Hold breath: Lizardfolk can hold their breath for up to 15 minutes at a time.
Hunter's lore: Lizardfolk gain proficiency with two of the following skills of their choice: Animal Handling, Nature, Perception, Stealth, and Survival.
Natural armor: Lizardfolk have tough, scaly skin. When they aren't wearing armor, their AC is 13 + Dexterity modifier. They can use their natural armor to determine your AC if the armor they wear would leave them with a lower AC. A shield's benefits apply as normal while they use their natural armor.
Hungry jaws: In battle, Lizardfolk can throw themselves into a vicious feeding frenzy. As a bonus action, they can make a special attack with their bite. If the attack hits, it deals its normal damage, and they gain temporary hit points (minimum of 1) equal to their Constitution modifier, and they can't use this trait again until they finish a short or long rest.