When Alice returns with the meat, Cat ties it to her 30ft rope and throws it at the waterline, then slowly pulls the rope with jerky movements as if fishing. She's  staying as far away as possible (30ft) and if a monster moves too close falls back to the others.

Alice arrives with 2lbs of dog meat and skewers it on Cat's grappling hook which is tied to the rope.
Cat swings the rope and tosses it at the waterline so the meat touching the water becomes palpable to underwater organisms. Cat pulls on the rope, it's jerky movements mimicking tasty bait wriggling in the water. Slowly pulling it back, Cat attempts to lure one of the creatures out of the water, or at least make them surface.

The goal is not 'fishing' (or rather snaking, octopussing), as it getting the prey entangled on the rope as even Cat would not be able to pull the huge creatures out. The goal is simply to lure one of them out of the water so they can be range-attacked and eventually separated and flanked.

Attacking both of them would be suicidal. We would have to take out one with ranged attacks first before we can enter melee with the other. I still assume only the snake can move on land as the octopus probably can't support his own body weight without the buoyancy of water. But what do I know, it appears this octopus can do it all.

Of course any creature that surfaces should also be stung by a wasp. We probably have to wear one down like this with ranged attacks only. The question is how long that works before they realize they only take damage without prospect of food and won't come out without a victim in range. That's why we have to offer them a reward as well. If that's not enough Cat will probably have to pile up more dog meat garnished with ghoul. Can you even eat them? Let's find out.

So the plan is - meat fishing - meat pile - live bait (summons or me). We gotta keep them entertained with different bait or they won't come out after a few hits. But we can't communicate this while deafened

In the aftermath of the ordeal, 10lbs of meat has been lost by various methods, activity at the water's edge included precision strikes by stray tentacles, adeptly pulling bits of meat off the line with zero repercussions.

Ashley addresses the group. Listen up, this whole weak arrow attack and ranged crap with cantrips isn't going to work, we have one chance. Alice, once Moby-Dickapus is held and beached, get in there and grapple it like Brutus said, attack with everything you got, all the hits you can with your hand harming thing.