* Caddy submits his thesis research; and although his results are inconclusive, his unique approach to the subject of Green Magic and patient wellbeing gets him aĀ āleg upā, opening up the possibility of further post-graduate research. He doesĀ graduate from NHU eventually, and gets his doctorate in Healing, with a minor in Exotic Languages (Wingdings). He eventually worked his way up through the ranks of New Home General to take over as head of the CMBD Ward, as well as supervising research into the applications of Green Magic. Dr. Greenburg is able to focus on pioneering Soul Surgery, and has several techniques named after him before he retires.
* Gaster proposed to Caddy in Waterfall, on their anniversary. They were married in a small but intimate ceremony, with King Asgore himself reading the vows. Everyone from the various timelines attended - including the Benevolent Stranger (who showed up at the end of the Bauhaus event). They reveal themselves to be Caddings Brewster, aĀ āfusedā Caddy and Gaster from a timeline where G continued his self-experimentation, and was saved by a magic unique to his timeline. Theyāve been watching the timelines and - having lived through aĀ āPacifist Endingā closer to the original Undertale - they want to help prevent the bloodshed that got their Underground to the Surface.
* Caddings shared their research notes with the other Royal Scientists of the various timelines, and this led to several developments. First, using magical techniques from Caddingsā timeline - Bauhausā dust, the remnants of his SOUL, and the newly-reformed Purple ParasiteĀ āCinnamonā were used to create a new being, Freshaus. Retaining few memories of the pain theirĀ āparentsā caused, and a mental age of 10-12 years old, they were raised by Gās family. Itās a second chance for Bauhaus, and a chance to be an ordinary monster for Cinnamon.
* And second - with the combined efforts of the Fallen Children of various timelines, the monsters reached the surface years later, without any bloodshed. The various timelines remaining in contact with one another, of course!
* Dagwood and Toonster are married in their series finale. Their traditionalĀ āwedding chaseā is interrupted by the arrival of Frisk, a human with the power of Creativity - and their run across the whole Cartoon Underground turns into a race to set every Toon free, before the Script can catch up to them and write them into more wacky hijinks. Needless to say, thereās a happy ending - Papyrus is able to change his alignment (thanks to a mask and cape drawn on by Frisk) and grows up to be a superhero, with Sans as his sidekick. Dagwood takes up the most boring hobbies possible - such as stamp collecting, and fishing without bait or hooks - and brings Toonster along for the not-at-all-exciting ride. They couldnāt possibly be happier.
* The adults from the Underswap household get married, in a ceremony presided by Seamus, followed by one of the craziest receptions their timeline has ever seen. Following this, they collaborate with Zero and Taffy, and spend a few years traversing the timelines in aĀ āTimeshipā, finding ways to set their ownĀ āPacifist Endingsā in motion. Eventually, they hand the reigns of their mission (and the keys to the ship) over to the younger generation, and can rest happy knowing that the timelines are in good hands.
* Taffy and Zero both retire from full-time adventuring. They open an all-vegetarian sandwich shop,Ā āSub Zeroā, just outside the Ebott Nebula, and continue exploring the environment on the weekends. Talks with the Human Federation have begun in the background - but they donāt concern themselves with human affairs, unless thereās a budding Xenobiology or Arcane Engineering student with a book for them to sign. And even with the lack of meat, Swap Sans is one of their best customers - he stops by once a week along with Outertaleās Sans and Pap (all of them long since grown up) to update them on their ongoing quest to make friends, have adventures, and set monsters free.
* Wingdin and Bitter run a bakery in New New Home, conducting inter-timeline deliveries, and inviting any Caddy or Gaster to come in any time for a friends-and-family discount (which everyone takes them up on). Cupcake enjoys a somewhat early retirement, stopping only to maintain the delivery system, and of course eat pastries. Seamus makes it to see the Surface, has a few more happy decades with his family, and even visits Ireland, where his ancestors came from. Edge takes up woodcarving, enjoys some genuine Cuban cigars, and passes away peacefully at the ripe old age of 350. Both live to see their grandchildren. Both are surrounded by loving family and friends when they go - and their dust is scattered into the winds atop Mt. Ebott.
* Chip is probably the most āquietā on the communication front, but things seem to be going okay for him and āCrazy Gā. He stops by the New Cozy Cafe once in a while, but mostly sends his updates to the others via telegram, and talks about humans and monsters marching together for equality. He proudly shows off a missing tooth, claiming he lost it while defending a downed human from a cop who was kicking him. Help is offered various times, by various Caddys in the cafe, but he always declines - change is coming, but it has to be at its own pace.
* Gaster, meanwhile, never Falls in the Alpha Timeline, as monsters reach the Surface before another child ever falls. Heās happy to retire as Royal Scientist, allowing Alphys and Sans (now graduated with multiple doctorates) to handle things such as allowing the CORE to be used on the Surface. And along with Swap Papyrus and some of the other Sanses, theyāre working together on getting Chrono stable enough to leave the void, and narrowing down the co-ordinates of his home timeline. Maybe they wonāt be able to save everyone, but that doesnāt mean they wonāt try. Every day, they get a little closer.
* And reaching the surface, Caddy stepped back into semi-retirement, performing home visits for monsters with CMBD so he can spend more time with Gaster. While Dr. G refuses to travel by plane, they celebrate their lifeās achievements with a round-the-world cruise. And during a stopover in Europe, Caddy calls his moms (who are both happily married and also retired), and finds out that Sans and Papyrus have befriended a human named Frisk. They were adopted by King Asriel and his partner - and looking at the newspaper photo of them and their Untie Chara, of course they look very, very familiar.
Caddy and Gaster conclude that the more things change, the more they stay the same. They head back to the cruise ship, knowing thereās an all-you-can-eat buffet, and if they can manage it, ballroom dancing to look forward to.
They are happy.
And they hope that their human friends are happy, too.