Monster initiative: 5

The monster howls. Everyone's turn.

"Maledictus Canis!" shouts Glory as a black energy settles over the former cub. (Hexblade's Curse)

She charges up to the beast and slashes with her sword. Attack: 16 Damage: 12

Varis pulls out his rapier and aims for the gooey center of the wolf:

Attack: 14 Damage: 6 + sneak attack: 8

Yuldra looks despairingly at the whip she'd been using as a leash. Well, could be worse, at least with it's head split in two the puppy was no longer on the other end of it. She swings the lash at the monstrous winstonian lump - Attack (Pact weapon - Whip): 15 Damage: 6 - using the gap it affords her to stay out of it's range, then backs away to cower behind her colleagues.

Endurance takes a swipe with each longsword: 8Attack: 7 Damage: 10

Attack: 14 Damage: 7

Assuming the second one hits, it takes an extra 3 Damage and DC13 wis save or frightened of me until end of my next turn. 

Creature.

Algae Vs Yul: Hit:25 Dmg: 14 STR 6

Algae Vs Endurance: 19 Dmg: 17 STR 6

Chomp Vs Varis: 22 Dmg: 7 Slashing + 5 Poison

The party springs into action to deal with the new threat. Glory quickly slashes one of the algae appendages while Endurance pierces another (1 attack hit). Yuldra whips the former cub in what used to be its head. Varis moves in to stab it in the soft mouth but quickly realizes that it isn't a good idea and tries to back off. Before he can get away, he finds himself being caught between the "teeth" of the creature. The creature flails two of its arms, trying to grab Yul as it lashes out toward her and trying to knock Endurance away from it. The algae wraps around Yul and begins crushing her but she manages to get slip away from the creature's grasp. Endurance quickly dodges out of the way as the large appendage slams on to the ground.

Everyone's turn.

(Generally, I spend the rest of my movement getting out of range being a swashbuckling rogue type, but since I didn't type it I'll take it...am I grappled now, though?)

Nah, the bite attack doesn't grapple.

(it needed the wis save unless it is immune to frighten)

Reaction: Riposte: Attack: 6 Damage: 11

Action: Attack: 23 Damage: 5

Bonus action: Attack: 8 Damage: 5

The pressure of this place with all its craziness seems to be taking its toll. (I mean what is the chance of 2 nat 1s in that post) 

Glory slices at the creature.

Attack: 17 Damage: 9

Given the dogmantilgae's immense reach, Yuldra hangs back, coiling her whip around her forearm and then air-punching an eldritch blast at the beast : Attack: 13 Damage: 8

The creature isn't immune to frighten. I just didn't see that part of your post. 15 (It passed the save)

Endurance launches into a flurry of swings but all of his attacks miss. Glory takes this time to stab into the creature with her sword.

Yuldra, do you move back? I wasn't sure.

Varis dances back in with another rapier attack:

Attack: 15 Damage: 4 sneak attack: 10

Then he'll dance right back out of reach

Quote from ZulkRS >>

Yuldra, do you move back? I wasn't sure.

 (Ooc : yes, that was the intent in the first round - use the whip's range to hit and run. 2nd round just stay back. I wasn't clear on whether I started off in range in the first place though! ;) )

(Oh okay. I misunderstood. Actually the creature's bite has a  range of 5ft but does more damage. The algae that attacked you is very elastic and can stretch to 30ft. I misunderstood that you were falling back in the first round. I'll be more mindful in the future.)

Creature AoO vs Yul: 23 Dmg: 15 STR: 16 (DC13)

Chomp Vs Yul: 19 (Adv: 16) Dmg: 12 Slashing + 4

Crit Damage: 19 (total)

Algae Vs Glory: Hit:12 Dmg: 19 STR 6

Algae Vs Glory: Hit:12 Dmg: 9 STR 4

Algae Vs Endurance: Hit:17 Dmg: 8 STR 20

(3 alage attacks this time?) 

Yul moves back and hurls an Eldritch Blast that flies by the creature's body. As she does so, the creature lashes out with its algae appendage, wrapping around her as she tries to escape. Giving Yul a good squeeze which probably breaks a few bones, the creature quickly brings her close to its mouth and chews her up like a chew toy until she goes limp. (DEATH SAVE)

Yul takes: 3 Sanity damage for getting crited.

Varis quickly jabs his rapier into the creature's flesh, causing the monster to yelp in pain and drop Yuldra to the ground. Varis then runs far away from the creature's reach. Now pissed off, the beast trashes about its algae, hitting Glory in the head and bringing her down to within an inch of her life (1 HP).  Glory manages to protect herself with her shield for the second strike.

Glory, Endurance and Varis.

Yuldra: Death Save

Quote from Swiftgale >>

(3 alage attacks this time?) 

 Yeah, this thing has multi-attack where it can make 2 algae attacks and a bite or 3 algae attacks.