Actions

When a monster takes its action, it can choose from the options in the Actions section of its stat block or use one of the actions available to all creatures, such as the Dash or Hide action, as described in the Player's Handbook.
Melee and Ranged Attacks

The most common actions that a monster will take in combat are melee and ranged attacks. These can be spell attacks or weapon attacks, where the "weapon" might be a manufactured item or a natural weapon, such as a claw or tail spike. For more information on different kinds of attacks, see the Player's Handbook.
Creature vs. Target. The target of a melee or ranged attack is usually either one creature or one target, the difference being that a "target" can be a creature or an object.
Hit. Any damage dealt or other effects that occur as a result of an attack hitting a target are described after the "Hit" notation. You have the option of taking average damage or rolling the damage; for this reason, both the average damage and the die expression are presented.
Miss. If an attack has an effect that occurs on a miss, that information is presented after the "Miss:" notation.

Multiattack

A creature that can make multiple attacks on its turn has the Multiattack action. A creature can't use Multiattack when making an opportunity attack, which must be a single melee attack.

Ammunition

A monster carries enough ammunition to make its ranged attacks. You can assume that a monster has 2d4 pieces of ammunition for a thrown weapon attack, and 2d10 pieces of ammunition for a projectile weapon such as a bow or crossbow.