You get out of the channel and continue through the exit opposite to the way you came. Walking over the bloody trail you are about to enter the next room as you hear the sound of slight clicking and cracking.

Peeking around the corner you can see a creature’s back. It is about 2 ft wide and 3 ft tall, covered in armoured plates, with a short tail and 4 legs all ending in a sharp point and has a serrated spine. The blood trail leads to it, or from it, and it seems to be looking at something which it obscured from your view by a natural cave wall.

Halhace will look at the creature and then to the others. "Would any of you perchance have any idea what that thing is and how we can kill it?"

It hasn't seen us?

Dhara puts her hand up to encourage silence.

(It hasn’t seen you yet )

Then without hesitation, I cast Hunter's Mark on it, pull out my longbow and fire a shot off.

Attack: 10 Damage: 11.  Hunter's Mark: 5

(incase i can roll stealth again, im trying to make sure the creature doesn't notice me. [my last stealth roll was 9 if that makes any difference])

Stealth: 3

edit: (oh god, i roll so many natural ones over all the games i am playing Xo )

In that case...

Everyone gets a sneak attack round, and roll initiative!

(Don’t worry EmperorKarino, it didn’t see anyone!)

Initiative: 21

That didn't go well.  I also move up just around the corner to the left (the first corner), which should put me out of sight for now.

Initiative: 6

(Any chance we get advantage on the attack rolls?)

 If Meep can see the creature, he'd start rambling, "Stupid, fat insect. Always block tunnel with fat head."

vicious mockery 4

Initiative 23

Halhace Initiative: 5

Bonus action: Shillalegh

Action: Toll the Dead DC13 Wisdom save

If the creature took damage previously(from one of the rest of the party or an existing injury) 9 necrotic damage

If the creature is undamaged: 3 necrotic damage

Initiative: 11

(No advantage sorry.)
Kamos, Halhace - do you want to do anything in the surprise round?

Dhara shoots first. Her arrow flying at the creature and as it collides with its armoured plates, the arrow bounces off.

Vicious mockery save: 17
Toll the dead save: 11

Meep’s mockery does not seem to faze the creature.

As Jaylen points at the creature, its head lifts in confusion at the sound of bells. It looks in the party’s direction, with big round black eyes and unnaturally sharp teeth. You can clearly see a fresh, deep wound just below its chin, where something seems to have taken a bite at it.
(It takes 9 points of damage)

Halhace will try to hit it with a Fire Bolt, his hands moving as he mutters the incantation for the cantrip.

Firebolt: Attack: 14 Damage: 3

Kamos is going to try to get close to the creature and punch it.

Movement: Kamos uses his full movement to get into melee range of the creature.

Action: Attack: (if in melee range) 16 (unarmed strike/bludgeoning)

Damage: (if it hits) 3 (bludgeoning damage)

Bonus Action: Unarmed Strike: Attack: (if in melee range) 11 (unarmed strike/bludgeoning)

Damage: (if it hits) 3 (bludgeoning damage)

edit: (before running over to the creature, i should have mentioned that i set the box we are delivering down on the ground)

Halhace hurls a mote of fire at the creature hitting it and leaving behind a small scorch mark on its armoured plate; although the creature looks more annoyed than hurt.
(It takes 1 point of damage)

Kamos nears the creature, hitting it twice and the creature shrieks in pain. After the attack, Kamos’ eyes fall lower, past the creature, where he sees a dead rat and two more of the creature, only these are much smaller – possibly young.
(-11hp to it)

Now it has definitely noticed you. It has turned to face you so you all get a better look at it.

Initiative order:
Meep
Kamos
Dhara
Small-Kruthik1
Jaylen
Big-Kruthik
Halhace
Small-Kruthik2

(EVERYONE, please state what you want to do in the first round, DON’T WAIT for me/the creatures to take their turn – this will take too long if you do.)

Updated map: