Can a creature finish its multi-attack after it pounces?

Question

If a creature has both the multi-attack action and the pounce feature, can it use both on the same turn?

Example: A Deinonychus (VGtM pg.139) pounces a PC. It rolls its claw attack roll, which hits, and the PC fails the resulting Strength save. The beast finishes its multi-attack — 1 bite attack and 1 more claw attack. And before the end of its turn it uses the bonus action to do another Bite attack.

Is that example's sequences of events correct?

Answer 1

This is correct.

Noe that the Pounce feature is in the Special Traits section, and not the Actions section of the entry. This means that if the monster fulfills a certain set of criteria, then something extra happens. The action that the monster actually takes is still the multiattack option. In your example, it would go like this:

• Deinonychus moves 20 ft.
• Deinonychus uses multiattack: it hits with claws
• Pounce is triggered, target attempts and fails the saving throw
• Deinonychus completes its multiattack with a claw and bite attack
• Deinonychus uses its bonus action to make another bite attack

Contrasting this with an Action

The Gelatinous Cube, on MM 242, has an Engulf ability under its Actions section. This means that if it takes the Engulf action, it cannot use its pseudopod attack, because both are actions. If the Engulf ability were outside the actions section, the way Pounce is, it no longer takes an action to use it, and so it could engulf and attack on the same turn.

Answer 2

That's correct.

Nothing in the rules prevents a creature with Multiattack from taking a bonus action. This is all the DM's Basic Rules and Monster Manual have to say about Multiattack:

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

Although it wouldn't matter in this case, the bonus action bite could occur before the deinonychus finishes its Multiattack. See the Player's Basic Rules or Player's Handbook, under Combat, The Order of Combat, Bonus Actions:

You choose when to take a bonus action during your turn, unless the bonus action’s timing is specified, and anything that deprives you of your ability to take actions also prevents you from taking a bonus action.

The only requirement for the bonus action is that it occur after knocking the target prone, so it can occur during the Multiattack. This doesn't prevent the Multiattack from finishing.

Additionally, Jeremy Crawford (the lead rules designer for 5th edition's rules) has confirmed that the bonus action from Pounce occurs on the same turn, just in case there was any doubt.