Globgor is a monster with red skin covered in darker red tiger-like stripes, long white hair tied into a topknot, four yellow eyes with slitted pupils, pointy ears and nose, short horns, and fanged teeth. He wears a black boxer-briefs-like garment, gold wristbands, and a ring on his left ring finger. According to Eclipsa in "Total Eclipsa the Moon", he also has a tail similar to Meteora's.
In portraiture and other dramatized depictions, Globgor stands a little more than twice the size of Eclipsa. In "Conquer", he is shown to be of gigantic size. This is thanks to his abilities as a size shifter.
According to Star vs. the Forces of Evil: The Magic Book of Spells, Globgor, referred to in Eclipsa Butterfly's chapter only as "the Prince of Darkness", first met Eclipsa when they were both relatively young, during the reign of Eclipsa's mother Solaria. As war was waged between Mewmans and monsters, Globgor and Eclipsa met in secret and slowly fell in love, though at one point Solaria discovered them and believed Globgor was trying to kill Eclipsa.
Globgor and Eclipsa would continue to see each other up until Eclipsa inherited the Royal Magic Wand and Solaria was assassinated by a rebel faction of the monster army. Despite the war between their respective races, they advocated for peace between Mewmans and monsters. After Eclipsa married King Shastacan Spiderbite and the Mewman-monster war grew more violent, Globgor convinced Eclipsa to leave with him, promising that she would be welcomed among the monsters for a brief period.
As revealed in a passage in "Into the Wand" and trial testimony in "Butterfly Trap", Eclipsa accepted Globgor's invitation, abandoning Shastacan and Mewni in order to be with him. They and the rest of the monster army left and found refuge in an ancient monster temple, where Globgor and Eclipsa later bore a half-Mewman, half-monster daughter, naming her Meteora.
The Magic High Commission eventually discovered where Globgor and his army were hiding. Globgor was crystallized and remained imprisoned at the temple, while Eclipsa was imprisoned in the Crystal Dimension for breaking the Mewman taboo of fraternizing with a monster. Their daughter Meteora would later be disowned by Shastacan, adopted by St. Olga, and replaced with the peasant girl Festivia.
At the end of "Conquer", after Meteora is defeated and reverted to an infant, Eclipsa brings her to the Monster Temple and discovers where Globgor still lies in crystallized stasis.
In "Butterfly Follies" and "Moon Remembers", Eclipsa's monster subjects work to try and free Globgor with pickaxes and chisels, but according to Moon Butterfly, such methods are ineffective against Rhombulus' magic. In "Swim Suit", however, his right hand and a piece of his hair are freed by Eclipsa using Rhombulus' powers through a body-swapping spell, later to be recrystallized by Rhombulus himself at the end of the episode.
In "Surviving the Spiderbites", Globgor is revealed to have a dark history with the Spiderbite Kingdom in particular, infamous for burning down the Spiderbite village, devouring King Shastacan, and having numerous pieces of monster art and culture as tribute to these acts.
In "The Monster and the Queen", Eclipsa enters Globgor's mind when he is still crystallized and goes on a date with him inside his subconscious. Though Eclipsa tells him she's ready to set him free, Globgor laments that she shouldn't do so unless Mewni is ready for him. Thus she waits until a coronation she agrees to let Star organize. But he is finally freed from his crystal in "Cornonation" and he flees to protect his family. But Star intercepts him and he returns chained up. He breaks free to protect Eclipsa from the fiercely accusing Magic High Commission and the people are touched by his determination to protect his wife and child. Eventually it's revealed that Rhombulus was the one who set him free to trick everyone into seeing what a monster he is, getting himself imprisoned as punishment and Globgor and Eclipsa are coronated with a unanimous agreement from the Mewmans and monsters watching.
Role in the series
After learning about being ratted out by Prime Major Admiral Asper Swipe despite him promising to keep quiet just to get them off his scent, Globgor swears to destroy him in Asper Returns when he comes back trapped in his disgust in the body of a monster species his own species were at war against previously, seeking to become a Xexaxez Avatar to destroy monsters when he discovers Mewnian monsters did a similar sin millions of years ago, and reforge his original body which was previously unable to interact with anything unless his Ghost Prisoner Spell was undone by the caster, Lord Millipede. It's made worse when too much is learned that Glossaryck had known involving The All Mother, driving him into a desperate campaign to save both monsters and Mewmans and eliminate both Asper and his other hated enemy Seth of Septarsis.