Glossaryck, or Sir Glossaryck of Terms, is the living embodiment of the Magic Instruction Book for Star Butterfly's magic wand, and Star's guide in magical matters, as well as the creator of the Magic High Commission and father of it's members Omnitraxus Prime, Hekapoo, Rhombulus, and the deceased High Chancellor Lekmet, whether adopted or magic-born is unspecified. His first official appearance is in "Mewberty", but he makes some cameo appearances beforehand in "Star Comes to Earth" and "Monster Arm" before becoming a recurring character. He is burned into ashes in "Book Be Gone" along with the Magic Instruction Book, but he is restored in "Rest in Pudding", then dies for good along with the Realm of Magic because of being magic itself, accepting his death claiming that a good captain always goes down with his ship. Voiced formerly by Jeffrey Tambor (Big Nose in the Tangled franchise, King Neptune II, and the Mayor in the live-action Grinch), he is now voiced by Keith David (Goliath of Gargoyles, Doctor Facilier, Tublat, and Gary the Snail's Chatterbox Translation Collar).
Glossaryck is shown to be very wise, but he can be very silly and playful at times. He is known to be overly cryptic in his advice, and quite sarcastic. He also has a recurring fondness for pudding.
Despite this, Glossaryck takes his job seriously and understands the importance of preparing Star for queenhood. However, he views friendship as a "simple concept", and his loyalties appear to shift depending on who is in possession of the book of spells. According to Glossaryck himself in "The Hard Way", he does not "have a side", indicating he takes a largely neutral stance during conflicts. The other members of the Magic High Commission agree that Glossaryck is very unpredictable and prone to doing his own thing, earning him contempt from others such as Rhombulus.
As of "Stranger Danger", Glossaryck has an impaired mind since his restoration, capable of little more than basic motor skills and repeating the word "Globgor!" This, however, is revealed to have been a complete ruse in "Conquer", with Glossaryck possessing his full intelligence from the start as he was simply trying to tell the characters that Eclipsa is going off to be with her monster husband Globgor for months.
In "Meteora's Lesson", it's revealed he has a giraffe person son named Reynaldo who operates a boat in a time-travel river and used to be part of the Magic High Commission, which he created, before being kicked out for constantly speaking in annoying riddles. When he took Meteora with him there, he ends up creating the royal magic wand for Mewmans who lost their memories in a river from the Realm of Magic, and the first Stump Day. He even ends up meeting Toffee in the past who broke his right arm earlier for making a 'stupid leaf hat', and ends up almost getting his soul sucked out by Meteora.
He is also noted for being all-knowing, knowing how things would transpire by the end of the series. All he does throughout the series was meant to prepare for his true death in "Cleaved", showing Star the consequences of destroying magic in "Tavern at the Edge of the the Multiverse" as he is magic itself and she wouldn't be able to see Marco again because the magic would send him back to Earth, especially since the two recently became a couple. He prepared Star, Moon, Eclipsa, and Meteora for the mission to destroy magic, especially giving them the immunity to the Realm of Magic's amnesiac effects: his favorite treat pudding. When the Realm of Magic begins to die, he accepts his fate, claiming that a good captain always goes down with his ship.
Role in the series
Glossaryck is revealed to have two relatives: a sister named Indexyca who was assigned to Prime Major Admiral Asper Swipe's magic spear guide and loves gelatin as opposed to Glossaryck's love for pudding, and a cousin named Contentyck who was assigned to Archduke D'oughe Bagg. In Asper Returns, he's revealed to not only be a former Infinitary whose real name is Glossiary, but knows the entire history of Mewni and what is in store for it including not just The Xexaxez that destroyed Mewmans' original home, but also knows that the monsters of Mewni had a similar fate in that they were not only wiped for using magic dangerously, but resurrected by a Resurrectorate who took away their gift of magic when they half-failed their test because of it. Glossaryck created the Magic High Commission from other Infintaries to have monsters and Mewmans learn from each other so that they could never repeat history, making himself numb about who dies and at least somewhat pretends to like people, not because of a lack of caring, but because he was trying to learn empathy in hopes that he could show these teachings to other outer gods in hopes to cure what he deems to be self-harming and/or counter-productive practices, hoping to inspire the Outer Gods empathy and compassion after being distroted about how Outer Gods work, reacting poorly to how miserable of an existence it is for cosmic level beings, though until he can achieve this, he ensure the situation was kept within control, making the commission just as amoral as him to make it possible to learn emptahy, hoping to introduse a new purpose for the outer gods and get them to undo their woes, like getting Deity Quellers to cure inrealm gods of morality illness, give or take the deviented demon worthy of such, and to spare Outer Gods of going to the Hybernation Realm, save for legit threats like the Plainspawn and Butcheroth Protothus, as well as doing anything he wants for the same reason, only meaning well for the greater good of Multiverses present and to come, but this attracts the attention of The All Mother, who sees this as against the grand design and could put so many in The Multiversal Hierarchy out of existence, as she has Mewni targeted by so many Outer Gods by claiming Glossaryck was a threat, which is not only how the Xexaxez assigned to Mewmanity found them, but also is the reason why Mewni is under threat of annihilation. Though when this is revealed, he is turned away by everyone for causing so much misery and putting everyone in danger, even inspite of Glossaryck's pity-worthy crying and begging of meaning well, even having gotten wounded in the process. It wouldn't be until the rescue from the Willtopians would Glossiary be forgiven-ish in understanding him better, or at least as well as they could. Though what Glossaryck does seems evil, he is actually amoral and does good in his own weird cryptic way.