Manuel Delgado Villegas was born in Seville, Spain, on January 25, 1943. He was the son of José Delgado Martín. His mother died during childbirth when she was only 24 years old. After his mother's death, Manuel and his sister Joaquina were sent to live with their maternal grandmother in Mataró. Their father had a job as a salesman selling arrope, a fruit concentrate used to make sweets. Due to his work, the family had a wandering lifestyle.

Manuel grew up in a neighborhood called La Cirera, which had many families from Andalusia. He went to school but faced challenges in his education and never learned to read or write. From a young age, Manuel identified as bisexual and began to engage in prostitution during his early teenage years.

In 1961, when he was 18 years old, Manuel joined the Spanish Legion. There, he learned hand-to-hand combat techniques, including one called golpe legionario, which is a strike to the throat with the edge of his hand. This technique would later become known to be one of his preferred combat methods.

After serving in the army, Manuel left Mataró and lived as a nomad along the Mediterranean coast. He survived by begging, stealing, and getting into fights with other people, including prostitutes and homosexuals. Manuel was arrested several times under laws in Spain that targeted vagrants and homosexuals, but he was never sent to prison. Instead, his strange behavior during these arrests often resulted in him being placed in mental institutions, from which he was typically released shortly after.

Manuel Delgado Villegas killed his first confirmed victim in 1964. He continued his crimes until his arrest in 1971. Delgado did not plan his killings in advance. Small comments made by his victims could set off his anger, leading him to kill them violently. He often used blunt objects, strangled his victims, or used his bare hands. He sometimes attacked people to rob them or, if the victim was female, to assault them sexually after they were dead.

His confirmed victims were diverse. He targeted both men and women, young and old, and individuals from different backgrounds. This made it hard for authorities to connect the murders to him until he confessed. Only the last two murders occurred closely together and in the same location, which helped lead to his capture.

The first known victim was Adolfo Folch Muntaner. He was a 49-year-old chef killed while sleeping on the beach in Llorac in January 1964. Delgado struck him on the head with a rock and then stole his belongings.

In June 1967, he murdered Margaret Hélène Thérese Boudrie, a 21-year-old French student. He suffocated her with a pillow, stabbed her in the back, and then sexually assaulted her body before taking a medal from her.

In July 1968, he killed 71-year-old Venancio Hernández Carrasco. Delgado asked him for food, but an insulting reply led to his murder. Hernández's body was later found in a river.

In April 1969, he killed Ramón Estrada Saldrich, a furniture dealer from Barcelona. After Delgado assaulted him during a sexual encounter, he bludgeoned Estrada and strangled him.

In November 1969, he murdered 68-year-old Anastasia Borrella Moreno. He hit her with a brick and later strangled her.

In December 1970, Francisco Marín Ramírez, a 28-year-old electrician and friend of Delgado, was killed. Delgado claimed he acted in self-defense after Marín made sexual advances towards him.

The final confirmed victim was Antonia Rodríguez Relinque. In January 1971, Delgado strangled her during a sexual encounter after she insulted him. He hid her body and had sexual relations with it several times before his arrest.

Following Rodríguez's disappearance, police questioned Delgado. After her body was found, he confessed to her murder and admitted to killing others. He was considered the perpetrator of seven confirmed murders but never faced a trial. He was placed in a mental institution due to a diagnosis of severe mental disorder. He died on February 2, 1998, from a smoking-related illness.