(The advantage from Help?  Lasts until the start of the familiar's next turn)

(Gotcha, cool.)

(I think you might of had to have chosen a specific creature to help, but just in case, here is the second roll)

21

The gibbering mouther has taken two crossbow bolts for 14 damage so far.

Aegean/Sssyd!

Quote from InfinityDM >>

(I think you might of had to have chosen a specific creature to help, but just in case, here is the second roll)

19

 (From my understanding when helping with attacks you don't have to pick a specific ally, because you aren't doing something to help a specific person's attacks, you're just distracting the enemy you picked.  You pick a specific person for help with skill checks)

Cat's wisdom save: 3

(Will edit if the cat fails it's save) Aegean's cat leaps, hissing, at the gibbering mouther again as Aegean's vision clears, Helping the next person to attack it.  Aegean blinks a couple times as his sight returns, then points to the creature and the sound of a dolorous bell echos through the room.

(Toll the Dead at the mouther, DC13 wis save or it takes 12 damage)

If Sssyd is able to move this turn:  Sssyd moves forward, swinging his scimitar at the hideous sight in front of him. 

Attack: 14 Damage: 7

If Sssyd is still stuck:  Sssyd will wave his arms, gesticulating wildly, trying to distract the creature, and Help whoever attacks the creature next.

The ground under the cat's paws is liquidized, demanding quick reflexes. Strength ST.

Wisdom ST: 6

Sssyd, you must make a Strength check. If you succeed you have advantage on the attack roll thanks to Aegean's familiar.

 Strength save: 3 (Though, unless the mouther moved out of melee range of the cat from last round, it could still do the help action and distract it)

(The mouther has moved 10 feet away. Forget that Help)

Donaar, Wisdom ST.

Quote from loathe >>

If Sssyd is able to move this turn:  Sssyd moves forward, swinging his scimitar at the hideous sight in front of him. 

Attack: 9 Damage: 6

If Sssyd is still stuck:  Sssyd will wave his arms, gesticulating wildly, trying to distract the creature, and Help whoever attacks the creature next.

 (It moved over to attack you, so i'd assume it'd be in range for you to attack back without moving either way.  Also, if the cat gets to do the help action after the failed strength check, you'd get advantage from it's help. I didn't do an attack roll, so i didn't use it)

Strength:  17

Attack w/adv:  Attack: 15 Damage: 9

Quote from JJWattaker99 >>

(The mouther has moved 10 feet away. Forget that Help)

Donaar, Wisdom ST. 

 (Could we get an idea of what the battlefield looks like?  I'd assume the gibbering mouther would have been ahead of all of us when it appeared, so after Ssyd moved towards it to try to attack, he stopped 10f away from it, between the rest of us and the creature.  Cat would have moved up without 5 feet to distract last round, presumably still in front of it between it and the rest of us.  Then it would only have had to move 5 feet towards ssyd to get into melee range, which wouldn't take it out of range of the cat)

(Recap: the gibbering mouther moved 10 feet on its turn, away from the cat and into melee with Sssyd. Sssyd hits with his attack and the cat failed it's Srength check to move. End result: Donaar is up.)

The gibbering mouther has suffered 28 damage by this point.

Wisdom:9 if I get an action:

Donaar chants some mystical words, and casts dust devil. A dust devil appears in a position that is next to the mouther, but not hitting any allies, if it can. 

Donaar quells the urge to panic.

(Who/what we waiting on?)

(I thought the dust devil would make an attack or take an action. If not, Merzin is up.)