This is some rescue! The porgs team up to free Chewie from the clutches of a monstrous underwater creature.
In the opening credits, BB-8 and a Star Wars ball lead the way followed by Rey, Maz Kanata, Finn, Captain Phasma, two stormtroopers, Ben Solo, Han Solo, Chewbacca, and three porgs.
Looking for their missing friend Chewie, the porgs come across the fishing rod and trident he'd left on the surface of Ahch-To. Figuring the situation out, the porgs dive into the ocean, armed with Chewbacca's trident, to rescue the Wookiee, who's been captured in a stasis-inducing bubble by a monstrous creature, alongside many others. Before Chewie has the chance to be eaten, the porg with the trident pops his bubble and wakes him up. Then the porg works to wake up all of the other creatures captured by the beast.
With it's dinner scattered, the Wookiee's original captor gets angry at the porgs and reveals its true ginormous form, rising from the bottom of the ocean high to reach for the birds and the Wookiee with its tentacles. They begin to swim away, but the monster follows suit. When Chewbacca starts falling behind, the porgs help him to the top.
Soon after they climb onto the rock, their chaser also surfaces, but there are more porgs here to help fight it off. The monster uses its hypnotic abilities to deal with the new attackers. Scanning their surrounding, Chewie comes up with a plan. He grabs his trident from the porg's beak, diving back into the water and jabbing it into the type of fish, attempting to catch which had caused all this trouble in the first place. Now aware of its violent, random reaction to getting stabbed, Chewbacca cleverly uses it to topple a spire onto the tentacled monster, which had been trying to ensnare the porgs into a new stasis bubble. Surprised by the falling rocks, the creature unwillingly puts itself to sleep and falls over into the water, leaving the birds and the Wookiee alone.
Chewie and the porgs celebrate their victory by roasting the very fish they'd used in the fight. When the meal is done, all of them bite into it, chewing happily.