Wing Din Gaster is the Royal Scientist of the Monster Kingdom of the Underground. He was created by the Royal Scientist before him, S. Keletonn.
Wing Din Gaster is a very tall skeleton with two vertical cracks/scars on his skull: one going from the top of his right eye upward, and one going from the bottom of his left eye down to his mouth. He has white pupils that dilate when he's angry and turn purple when he uses magical psychokinesis. He wears a light, black coat that goes down to his feet, which gives him the appearance of gliding, and a scarf to protect his sternum. Nothing is known of what he wears underneath the coat. He wears gloves with black circles on them with white designs on the backs.
Gaster is very professional, always speaking with proper grammar, except when he's angry. His professional tone stems mostly from his former and current occupation of Royal Scientist. After being shattered across time and space, he gained the ability to retain his memories from other RESETs, which allows him to be someone that Friskara feels she can talk to when she's having a crisis. His overall appearance and voice cause him to be unintentionally intimidating.
Though Gaster is somewhat intimidating and manipulative, he actually has a soft side for children and cripples. He is also very observant; he can read others' faces, and is often asked by the Royal Guard to help out with major cases. He hates bad puns, but chooses to put up with them for the sake of keeping his assistant, Sans. He enjoys science fiction and secretly goes to a blood bank on the surface every weekend.
His favorite television show is RWBY, though he would never admit it.
Gaster can quickly travel or teleport using Sans' "shortcuts."
In combat, Gaster uses "Gaster Blasters" to shoot a kind of laser beam. Gaster excels in combat and fights similarly to Sans, the exceptions being his attacks doing 15 damage and his Karmic Retaliation dealing 10 additional damage per second (for example, for the first 5 consecutive seconds after activation, it deals 150 total damage). Because of his research, he is able to use all types of magic attacks, including red attacks, which activate Karmic Retaliation.