A few references! (A wip because I got distracted lmao--)
I snatched a few of these from a magma with @oodlesndoodles (I took out Kale if only because I *was* planning on rendering before my distraction) but this doodle features Pretender!Sans, Paps, Gaster, Alphys, and Grillby in their monster forms!
(More rambles under the cut)
Design Choices!:
Sans: He's been underground for a long time but used to live on the surface. I imagine he *does* have the iconic Sans outfit somewhere, but right now he wears robes like the King and Queen used to. (He recieved them when he was appointed Judge by Asgore, but no one really knows their significance because only the Guard and Asgore know of his work.)
Paps: Chose his outfit mostly to match Pretender amd the Guard. His shoulder-pads are like old crystal ball props, and his cape had the same sparke affect as Pretender's hood/robes. Around his waist he wears one of the old lab coats Sans leaves around the house. (<- It belonged to one of Sans' favorite people, the one Paps tries to mimic, so he wears it now instead.) Paps has the markings on his face same as Gaster because Sans has a lot of photos from over the years hung on the walls in his room, and Paps used to see them a lot.
Gaster: He's deceased, so the current plot doesn't see him (he can't interact with K, unfortunately. I think they would've been friends if they'd met in Gaster's prime) but I still wanted to doodle him. This was how he looked towards the end of his life, when most of the lab team had passed and he was starting to fall down. He wore cardigans and sweaters, focusing mostly on comfort rather than safety (he was always cold, but especially so towards the end).
Alphys: Went a bit crazy after Gaster passed. She hadn't been eating for a long time, and she couldn't bring herself to leave the lab, even after Sans retired his studies and moved to Snowdin. She still wears her old lab coat, stained and ripped, and she's worse-off for it. Most who see her think she's a rabid animal that has taken a spot in the labs, cameras abandoned and traps scattered in the lab waiting for prey to fall into them. It's an unsafe zone. Any humans who manage to pass Undyne *always* fall to Alphys.
Grillby: Back to fun times!!! He's a short king (at least coming in at around 5'6" which is small compared to other boss monsters, but big compared to merchants) and still runs his restaurant in Snowdin. Though, it's usually empty these days since he doesn't exactly have much food to serve. And water? He doesn't touch the stuff. Sans goes there often just to keep Grillby company. Most monsters, even if they do see a human enter, won't bother attacking because they know Grillby gets first dibs. Grillby would rather not get blood on his nice counters, though. He wears a vest and button-up with symbols like Pretender's, but otherwise is fairly unchanged from canon.
Extra Notes:
-Alphys and Sans aren't on speaking terms any longer. After Sans gave up the project, Alphys became manic and fell into despair, deciding that she'd do everything herself. Sans tried to see her a few times after that before be realized she'd gone off the deep-end and he only dared to be nearby when Asgore needed him.
-I now believe that MTT would be a positive force for humans. A ghost-monster who wanted to look human, to see if they could pass the barrier. Alphys was in charge of the project before Gaster passed, and constructed a surprisingly sturdy human-like body. It was never tested against the barrier. Now MTT tries to stay by Alphys, even in her madness. He tries to help people by reminding them how humans look, act, and talk, with his show. He helps people who get caught by Alphys' traps. (Gotta talk to Ood, but I'm thinking that Pretender wasn't fast enough to help K on her first time through the lab. It was actually MTT who moved her out of immediate danger before stalling Alphys? Unsure.)
-Grillby likes the taste of human, but there are certain unspoken rules he works by, like other shopkeeps. For him, as long as you pay your bill and follow his one rule (no water (tears do not count as water)) then you're free from his harvest. If a human came in looking for shelter, he'd leave them be.
-Gaster was a brilliant mind, and Pretender took a lot of influences from him over the years. Despite his death, his image and memory lives on in the mannerisms and knowledge of those who knew him. In the grief left in his shadow. In the young skeleton who imitates him partially every day because he made his brother happy a long time ago.