I was wondering how the throwing of javelins work for monsters.

(This comes from a ptera folk statblock:)

I read that as an he can do multi attack, bite and 2 claws, or 2 melee javelin,

Or he can do not a multi attack, but 1 attack of the other options, including javelin throwing as 1 action. 

So can the pterafolk trow 2 javelins in his turn?  And what about the next turn? Does he have unlimited javelins? Or just 1?

Or is that dm magic to deside?

As ranged attacks are not listed under the pterafolk's multiattack options, it can only throw one javelin per round.  And it's the GM's call to determine how many they're carrying if it's not listed in their statblock.

From the intro to the Monsters Manual: (https://www.dndbeyond.com/sources/dnd/mm-2014/introduction#Ammunition).

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.

Quote from JonEros26746 >>

I was wondering how the throwing of javelins work for monsters.

 

(This comes from a ptera folk statblock:)

 

Multiattack. 

The pterafolk makes three attacks: one with its bite and two with its claws. Alternatively, it makes two melee attacks with its javelin.

 

Bite. 

Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) piercing damage.

 

Claw. 

Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) slashing damage.

 

Javelin.

Melee or Ranged Weapon Attack:+4 to hit, reach 5 ft. or range 30/120 ft., one target. Hit: 9 (2d6 + 2) piercing damage.

 

 

I read that as an he can do multi attack, bite and 2 claws, or 2 melee javelin,

Or he can do not a multi attack, but 1 attack of the other options, including javelin throwing as 1 action. 

 

So can the pterafolk trow 2 javelins in his turn?  And what about the next turn? Does he have unlimited javelins? Or just 1?

Or is that dm magic to deside?

 

Looks pretty straight forward: It can either bite and claw or use the javelin. No mixing and matching.