Monitor Lizards are a hostile mob that appears in hot, dry biomes such as deserts and mesas. It spawns during the day, seeks shelter at night (preferring lit areas), and hunts livestock. When killed, they drop a small amount of leather, helping to balance out the availability of resources in these biomes, just as goats provide food and wool.
Lizards have 10 hearts and are treated as wearing a full set of leather armor, giving them 28% damage reduction. If caught outside at night, lizards will take wither damage until dead, or until finding an overhang or an area lit by torches (glowstone, etc.) preferring areas that are both.
Lizards have a hunger-like mechanic that causes them to seek out and take down animals that drop food (cows, pigs, goats, etc.) and then systematically consume the dropped food items. After killing an animal or two, it will be satiated for several days, and if it feasted well enough (depends on the number of food drops and how long it took to find and kill its prey), it can slowly regenerate its health. Newly spawned lizards will start with a quarter of their food meter filled.
It will attack the player over attacking livestock, and if the player is killed, lizards will consume any food the player drops, prioritizing uncooked meat and rotten flesh over the cooked meat and other food items.