He wears a long black jacket, which is always left open. His right sleeve has a brown patch on it, possibly to cover up damage. He wears a light khaki scarf that, the further down, turns into a dark purple. The scarf also covers his mouth. His jacket, along with his loose grey shirt, have a unique symbol printed on them(Jacket has the symbol on it's back, and the shirt has it on the front.). He wears black pants and a tan pair of work boots; his left boot having multiple words in Wingdings printed across randomly. He has six Gaster Hands locked on his back, and more can be summoned.
Gaster is a bland being when it comes to emotions. He tends to hide his feelings and show no remorse over his actions; however internally he still has a heart. He doesn't regret his actions, yet wishes he had a choice to; though believes what he has done has been for the greater good. However, in his family's case, he regrets his actions on Sans; as the current version of Sans, Broken!Science, had became extremely damaged from what Gaster had done, making Sans have a deep disliking for G.
Gaster, also as a scientist, is a man of science. As from Project Vizion, he was one of the first in Vedomitale to discover and know of the Multiverse; as a result, he has expanded knowledge OF the Multiverse and some of it's AUs - Even more knowledge than Broken!Science.
Gaster is the husband of ??? and cares deeply for her. However, into the events of leading to Project Vizon and Evolution, the love between the two grew stronger. Up until ??? did something which eventually broke Gaster.
Gaster, externally, had hatred and emptiness toward Sans, as Broken has a deeper one for the opposite. The past the two have are the result of the hatred; even though they are father and son. However, internally, Gaster regrets everything he had done to Broken. As of current time, it is unclear is Gaster is even alive.
Gaster, unlike his opinions on Broken, both externally and internally loves Papyrus to bits. He has a heart for him to protect him from anything and everything if needed. However, because of this, Papyrus was left alone for large periods of time, left only entertained and protected by Fido during Project Evolution, which was unknown to Papyrus. He does NOT know that he ever had parents.
Gaster and Asgore are acquaintances; Asgore being Gaster's boss. The two handle the situation of escaping the Underground; up until the discovery of the Multiverse. After so, the two had parted ways due to something Gaster kept to himself. Asgore only knows that Gaster is currently missing.
- Gaster is the creator of the MTTD.