As the swarms approach her feet, Keyleth dances away (cunning action disengage), trying to find a spot she can stand which is out of the water (possibly by climbing up onto some of the dead vines), but failing that will simply move away as far as she can. She pulls out her crossbow, preferred to the longbow for shooting into water, aims at the fish, and fires.

Attack: 20 Damage: 14

Keyleth (21/21), Artus (?), Swarm1 (15), Timber (14/14), Swarm2 (?), Kirinar (28/28), Qawasha (5), Swarm of Snakes (7), Dr A (24/24)

Keyleth can't find a place to hide and the fish dart in and out of legs of the group.  She fires a crossbow at them and a few of the swarm are skewered, their bodies float to the top of the water.

Your studies of Volo's guide help and you recognize the fish as quippers.  You also fear that the snakes in the water are poisonous. Both foes will be resistant to Bludgeoning, Piercing, Slashing damage.

Artus pulls a dagger out and stabs at the snakes

Attack: 14 Damage: 7

Attack: 9 Damage: 7

Attack: 19 Damage: 7

He lands a couple blows.

The first swarm of quippers attack 

(When it is Kirinar's turn...)

The fighter lashes out at the closest swarm with his newly acquired magical weapon, attempting to stab or slash as many creatures as he can!

Attack: 23 Damage: 9

Since this is the first fight in several days, Kirinar is eager to strike, and surges forward to strike again quickly!

Action Surge Attack: 25 Damage: 6

At the sight of the quipper swarms, timber jumps back. "Nasty biting fish! Lets make it harder for them to make a meal of me!" He closes his eyes for a second, and all of the sudden there are 3 more copies of Timber poking their tongues out and blowing raspberries at the quippers. Mirror Image

Wild Magic: 12

"Now lets try and catch some." he says as he reaches out and out of his arm comes a skeletal hand that swats at the fish. Chill Touch

Attack: 22 Damage: 2

Keyleth (21/21), Artus (?), Swarm1 (17), Timber (14/14), Swarm2 (?), Kirinar (28/28), Qawasha (5), Swarm of Snakes (7), Dr A (24/24)

Timber mirrors himself and then (and I am assuming you spent 2 sorcerer pts to quicken a spell to do this as a bonus action) sends a spectral hand on one of the swarms.

The 2nd swarm of quippers bite at 

Dr A (1), Keyleth (2), Kirinar (3), Timber (4), Artus (5), Qawasha (6), T mirror 1, (7), T mirror 2 (8), T mirror 3 8 Kirinar

Attack: 12 Damage: 14 but they can't get to his skin to cause injury.

Kirinar strikes at swarm 2 and a couple of the swarm are killed. His second strike hits and the swarm is gone.

Qawasha produces a flame in his hand and throws it at the poisonous snakes 

Attack: 20 Damage: 2

but the water snuffs the flame out.

The poisonous snakes move towards

Dr A (1), Keyleth (2), Kirinar (3), Timber (4), Artus (5), Qawasha (6) 1

Dr.A 

Attack: 19 Damage: 8

 but he easily avoids them.

Dr. A is up!

Dr Arbutaveyu sees the swarm of snakes swimming around his legs and suddenly four glowing darts spear towards individual snakes as he casts Magic Missile at second level at them (14)

Keyleth (21/21), Artus (?), Swarm1 (17), Timber (14/14), Swarm2 (?), Kirinar (28/28), Qawasha (5), Swarm of Snakes (21), Dr A (24/24)

Dr A blasts the snakes with magic darts and most of the snakes die but a few remain.

Keyleth is up

Keyleth backs up further, and having neither a place to hide nor a mode of attack more effective than her crossbow, tries her best to skewer a snake or two with another bolt.

Attack: 23 Damage: 20

Keyleth (21/21), Artus (?), Swarm1 (17), Timber (14/14), Swarm2 (5), Kirinar (28/28), Qawasha (5), Swarm of Snakes (31), Dr A (24/24)

Keyleth successfully hits a few snakes.

Artus continues to slash at the snakes with his dagger

Attack: 22 Damage: 9

Attack: 16 Damage: 9

Finishing the snakes off he turns to the remaining quippers

Attack: 11 Damage: 6

Timber is up

(When it's Kirinar's turn...)

Kirinar moves to the last swarm of quippers, slashing at the biting fish with the oversized magical dagger they found earlier!

Attack: 19 Damage: 10

Timber searches for the final swarm. When he spots them he throws a warbling ball of energy at the swarm. Chaos Bolt.

Attack: 13 Damage: 14

 When the ball of energy hits the swarm, the colour goes green as it explodes into poisonous gas.

Keyleth (21/21), Artus (?), Timber (14/14), Swarm2 (24), Kirinar (28/28), Qawasha (5), Dr A (24/24)

Timber blasts the remaining swarm killing many of the fish. The few remaining fish swarm

Dr A (1), Keyleth (2), Kirinar (3), Timber (4), Artus (5), Qawasha (6), T mirror 1, (7), T mirror 2 (8), T mirror 3 8.

But they are fooled by one of Timber's mirror images

Kirinar slashes down with the Yklwa and cuts into the fish 

Qawasha tries throwing more fire at the remaining fish

Attack: 21 Damage: 4

and hits! Fried fish for dinner tonight as the last of the swarm dies.  The water settles down again.  Just you and a dead dragon remain.

Combat over

150 xp each 

With the snakes and quippers safely floating upside down, Keyleth lifts up some more of the dragon bones, lingering on the skull, looking for any clues that might suggest a way into the hidden door.

I'll need an Athletics roll if lifting the skull out of the water.   With advantage if  someone helps.   

Kirinar helps to lift the skull out of the water. As they do, he wonders if they could actually carry it out of the jungle - what a conversation that would be mounted above the door to his house!!

Quote from Rhanloi >>

Kirinar helps to lift the skull out of the water. As they do, he wonders if they could actually carry it out of the jungle - what a conversation that would be mounted above the door to his house!!

 Roll Athletics with adv

OoC: I am generally assuming that Kirinar takes the lead with any heavy lifting.

Kirinar rubs his hands together, gets a firm grip on the skull, and counts to three so that he and Keyleth coordinate their efforts. "1 - 2- 3!" Lifting with his arms and legs like his old militia sergeant had taught him, he slowly flexes and pulls and lifts until the skull is free from the muck on the bottom and the water.

Athletics: 25

With some help Kirinar lifts the skull of the dragon up so that the party can examine it.  Artus recognizes the bone structure. 

"See here,  poison glands would be present here.   I believe that this dragon would have been green, poisonous breath is what the green dragons are known for.   That may explain the dead plants killed by poison around the door.   The door is certainly big enough for this dragon to enter. "

"Well, then - let's investigate the doorway and see if we can find this dragon's treasure!" Kirinar says with excitement. But he doesn't immediately move towards the doorway, waiting for someone more observant or better at deducing how things work. He was better at deconstructing things. Quickly. With force.