The Great Papyrus is bursting with his signature over-the-top, loud, and confidently theatrical energy. He treats this leadership role with the utmost dramatic seriousness. Instead of a basic costume, he is sporting a flamboyant pirate captain outfit, complete with a large tricorn hat featuring a skull crossbones, epaulets, a high collar, and a sleek eyepatch. He is also known to throw on cool sunglasses, dramatically seasoning the parade route with pure festive flair.

Sans maintains his signature laid-back, lazy, and completely unbothered attitude for the parade. He balances out Papyrus's chaotic energy with a tired sigh, a permanent slacker grin, and his trusty bottle of ketchup always close by. Putting the absolute bare minimum into his costume, he sticks to his iconic style: his familiar blue hoodie, striped shorts, and white mittens. His only concession to Halloween is a large pumpkin mask thrown over his head, leaving just enough room for his casual—yet occasionally intense—gaze to peek through.

Undyne brings her wild, fiercely intense, and explosive energy to the parade, taking her role as the event's enforcer with extreme seriousness. Determined to maximize the morale Asgore wanted, she commands the crowd with a fierce grin, a sharp gaze from behind her eyepatch, and an intimidating aura that demands absolute order. For Halloween, she has elevated her usual armor into a stunning, dark samuray-style knight armor accented with deep red tones. With her long, fiery red ponytail flowing behind her and her glowing magical blue spear held firmly in hand, she looks less like someone in a costume and more like a battlefield commander ready to strike down anyone who breaks formation.

Asgore is radiating his usual gentle, warm, and deeply well-meaning energy, though he is completely clueless about the holiday. Wanting nothing more than to boost community morale, he is entirely convinced that this is a Christmas event rather than Halloween, offering a bright, hopeful smile to everyone in the crowd. Because of this festive mix-up, he has completely bypassed the spooky theme and is dressed head-to-toe in a plush Santa Claus suit, complete with a fluffy white trim, heavy winter boots, and a red hat neatly fitted between his large horns. Even when trying to dress down, his casual alternative is just his royal pauldrons paired with a simple straw farming hat by a bonfire, proving he is just a sweet, confused dad doing his best to spread holiday cheer.

Mettaton brings his absolute peak glamorous, dramatic, and intensely attention-seeking personality to the parade. He views the entire Halloween event as his personal runway, striking fabulous poses and ensuring every single camera and eye in the underground is locked dead on him. For his costume, he has completely embraced a stunningly theatrical vampire look. He is wearing a sleek, high-collared dark cloak with vibrant purple and pink gradients, a sharp formal vest, and elegant gloves. He pairs this gothic elegance with a dramatic, sweeping hairstyle, prominent vampire fangs, and a toy laser pistol to effortlessly blend spooky season with high-fashion pop stardom.

Muffet weaves her greedy, elegantly mischievous, and subtly unnerving personality into the parade. She views the event as a goldmine for business, using her multiple arms to pour spider tea, offer pastries, and control intricate webs, all while wearing a sinisterly sweet, fanged smile. Her outfit captures a perfect spooky doll aesthetic, featuring a poofy, dark mauve and pink dress with a large prominent bow at the collar. She styles her hair into cute twin pigtails with tiny bows, which contrasts with her five glowing eyes. Surrounded by floating pastries, spider webs, and her pet spider, she brings a uniquely creepy yet refined charm to the parade.

Toriel radiates her signature maternal warmth, gentle kindness, and protective care, ensuring the parade stays safe and welcoming for everyone. While she fully supports the festive spirit, she balances the spooky chaos by offering a comforting smile, freshly baked pies, and a basket full of treats to hand out to the crowd. Her costume is an elegantly gothic and beautifully detailed regal gown, heavily featuring deep blues, whites, and intricate silver chains. She wears a delicate purple veil adorned with pink roses woven between her horns, and as a clever nod, a stylized Flowey hairpiece sits right at the center of her headpiece, perfectly blending classic elegance with Underground history.