Lillith is the daughter of Dracula. She herself is also a vampire, but one who likes the sun.
Created in 1988 by Michael T. Gilbert as the mother of the current Mr. Monster, Dr. Strongfort Stearn.
Abandonned by her real parents when she was a baby, Lillith was raised by vampire Mose and his wife.
Mose was present at a meeting of the Vortex (a cabal of demons) who were discussing what they could do about Mr. Monster. Mose remembered the story of how in medieval times the dragon Fin-Fa'ang lured a Mr. Monster to his lair. Having dropped oil, Mr. Monster's horse slipped. Drenched in oil, Mr. Monster was fried by Fin-Fa'ang's fiery breath. Despite not being present when Mr. Monster was killed, his son Sigfried Stearn gave his horse spiked hooves, thus his horse didn't slip when visiting the lair of Fin-Fa'ang. Stunned by surprise, the dragon's head was cut off by Sigfried.
This story gave Mose the idea that every Mr. Monster must have the memories and knowledge of their successors. To get rid of Mr. Monster, he concluded, the demons must break the lineage. The plan was quickly adopted by the Vortex and Mose was made vampire king as a reward for his great plan.
Studying Mr. Monsters, Mose waited centuries for the right moment. That moment came when Jim Stearn was left by his girlfriend Gloria Greene. Figuring that another woman could seduce him now, Mose handpicked Lillith as that woman. Knowing a human and a vampire can't reproduce, Mose thought that this would effectively break the lineage of Mr. Monsters.
Being attacked by a monster, Jim Stearn was recuperating in a hospital. Mose planted Lillith there as a nurse, who quickly was assigned to Jim. Jim fell in love with her and, fully restored to health, he asked her to marry him. Lillith told him she couldn't live with being afraid that Jim was constantly in danger while being Mr. Monster. Afraid of losing her, Jim quit being Mr. Monster.
To her horror, she became pregnant after they were married. Lillith tried to have a miscarriage, one time by throwing herself of the stairs, but every time Jim Stearn was present to save her and their unborn child. Their son came three months early and was born with his umbilical cord already severed. Jim and Lillith named their son Strongfort, after Jim's adopted father. Jim noticed that Lillith didn't take to Strongfort. She acted cold when Strongfort was around. As a result of the tension, Jim spent more and more time at the hospital and less time at home.
Planning to stop Strongfort from becoming Mister Monster, the vampire king Mose sent Lillith a letter, ordering her to take Strongfort to Stearn Mansion, his father's former headquarters, and kill him there. When Jim came home, he found the letter. After recovering from the shock of being married to a vampire who was out to kill his son, Jim decided he needed to become Mr. Monster again to save his son. However, vampires set his house on fire, trapping Jim inside. Contacted by the Fluorescent Five, Jim agreed to become Mr. Monster again in his prime for one hour. This agreement cost the life of one of the Fluorescent Five. After the hour, Jim's soul would be frozen in ice for eternity.
Jim Stearn arrived just in time to save his son from Lillith and her three vampire brothers (two of which Strongfort managed to kill himself). After Jim killed the third brother, Lillith shot Jim with a crossbow, killing him. Strongfort then took the arrow out of his father and killed Lillith with it.