Nobody's Perception: 18. 

Yanda's Perception: 14.

Nobody's Initiative: 27. 
(Refraining from rolling Yanda's until PM question clarified. Ignore the above rolls if misinterpreting anything.)

Nobody startled awake but took his time actually sitting up to look around. "What is it now?" He groaned while trying to rub the sleep from his eyes. As the sound of the horses incessant whinnying grew in intensity, the tiefling turned and gasped at the sight. "Wha--shit! E-everyone! On your feet. Now!" He barked at any still sluggish or asleep at the time but would send a barely awoke Yanda to shake awake those yet asleep while he turned to face the spiders in but his outer coat and undergarments. 

(Don't think anyone can beat a 27, so going ahead to post his action. Below subject to change if there's anything more to consider that Nobody would be aware of.)

Following a clipped series of arcane words, four green glowing darts of energy appear hovering over Nobody's hand. "A-away with you, Buggers!" He said curtly as all four darts zip from his hand and slam into the thickest portion of the swarm with lethal force. 

Movement: Spent half to stand up.

Action: Casting Ether Bolts at 2nd level at Swarm of Spiders, inflicting 4 plus 1, then times 4 for 20 Force Damage.

"Nine hells," Doyal swears as he tries to move the horses away from the spiders. The snapping of the branch does draw his attention for a moment as the tries to squint to try to catch a glimpse as to what cause the sound but when that proves futile, Doyal turns his full attention back to the horses and the approaching spiders.

Doyal Ini: 21

Fargen stirs (13) at the sound of the snapping branches.

 Fargen leaps up, as if he woke up sleeping next to a goblin.  "Spiders, damn it.  They'll burn soon enough."  Init: 9

Nobody 27 destroys most of the swarm But his familiar cant see half of what is going on by moonlight unless there is a camp fire

Yanda .

Doyal 21

M2 19

Fargen 13

Swarm of spiders 10 

M1 7

Thufir 6

Green means your turn.

With the spiders dealt with Doyal ties the horses to the nearest tree before turning to Nobody, "Watch the horses there is still something out there I am going to go check it out."

Doyal does his best to keep to the shadows as he enters the woods in the direction of the snapping branch, quietly as he can moving from tree to tree while trying to find any sign of what was out there.

Bonus Action: Hide 

Stealth 12

Action: Dash (to continue moving into the woods while in stealth)

Perception 17

ooc be right with you in the morning.

Nobody 27 

Yanda .

Doyal 21

M2 19 Moves to try and rustle itself a meal as Doyal sees a Giant spider shoot webs at one of the horses Attack: 21 Damage: 0  

Fargen 13

Swarm of spiders 10 

M1 7

Thufir 6

Green means your turn.

Fargen stands up unarmored and instinctively grabs his shield and eyes his weapons at his feet beside him.  He peers out into the night with his darkvision for the attacking spider

"Vile are the creatures of the night and the poison they bring." he grumbles.

It had to move within 30ft to get a good webbing on the horse so yes.

Fargen draws forth radiant energy and unleashes a ray of light at the spider.

Attack: 19 Damage: 19 radiant (on hit, next attack has advantage)

Nobody 27

Yanda 

Doyal 21

 M2 19 The spider now glows with a radiant energy and is bloodied

Fargen 13

Swarm of spiders 10

M1 7  Moving in from above about 30ft This Giant spider attacks with a web shot at Fargen Attack: 6 Damage: 0 

Thufir 6

Shaking the sleep from his eyes, Thufir runs up towards the, now glowing, spider, putting himself between it and their mounts, and swings his new weapon at it.

Nobody 27

Yanda 

Doyal 21

 M2 19 The glowing spider is cut in half by Thufir's first cut but he cant reach the other being higher up in the trees.

Fargen 13

Swarm of spiders 10

M1 7  

Thufir 6

Green means your turn.

"O-Oh great! G-Giant One's too!" The tiefling complained after whipping around to trace the web shot path. Though he soon relieved seeing the one dispatched with swift efficiency, the other yet remaining soon earns it a scowl. "O-Oi! Get down from there you eight legged fiend!"  In a few quick gestures and an arcane phrase, Nobody fans out several magical darts in his hand and flings them with again uncanny precision. 

As all that is happening, Yanda crawls his way over to his master's ankles after much blind searching around, and holds on for dear life. 

Action: Casting Ether Bolts at 2nd level at M1, inflicting 2, then times 4 for 8 Force Damage.

(Queued after Doyal's action)

Fargen steps aside the giant spider's sticky web and responds with another ray of light at the large vermin.  He picks up his warhammer and advances to support Thufir.

Attack: 25 Damage: 14 radiant

With the presumed source of the snapping branch now found Doyal pulls his shortbow off his shoulder, knocks an arrow, and drops to one knee. Now in  his new stance keeping his hand steady Doyal takes aim at the giant spider and looses the arrow.

Bonus Action: Steady Aim

Shortbow Attack: 15 Damage: 7 plus 7 Sneak Attack damage

The giant spider raises it's two front legs as if to attack. But it turns more defensive with the onslaught of attacks from the ground. With the last hit it glows and explodes leaving glowing spider parts and goo everywhere. 

The night is calm again after a moment the frogs and creatures of the night continue their song, absent during the attack.

(You're out of combat.)

Nobody just stands there for the first few moments looking about for any other eight-legged terrors in the deep. Only when nothing comes of that would he start to breathe a sigh of relief before a cool breeze reminds him to cover up a bit more. "Well this has been a pleasant evening so far. Bloody hell. And to think those creatures hadn't the decency to die a little further away from camp at that." He complained. Although it quickly becomes apparent in tone and the smirk the words were meant at least in part in jest. "Is everyone else alright? No too serious injuries I hope?"

Rp with others and to bed and then, we will continue.. 

Fargen packs his pipe and sparks an ember to ignite his leaf.  He looks over at carcasses, "Damned things are unsettling to look at, even dead."

He eyes over his new companions a little differently now, as he's seen them in battle.  The tiefling moved so fast.  They'll pair well in a fight.

At the break of dawn, Fargen approaches Doyal, "Adventuring is dangerous business.  If you will, I'll grant Moradin's Blessing to your armor this day."  If Doyal agrees, Fargen imbues Doyal's studded leather with abjuration magic (+1 AC).  Fargen prays to Moradin for safe travels and an amicable horse.