An Upir is a mythological creature from Eastern European folklore. In Russian stories, they are a type of vampire or ghoul, who feeds upon the blood and flesh of their children and family. Upirs differ from traditional vampires in that they can walk about in daylight unencumbered, though many stories also posit that they will sleep in the graves of an unfaithful or sinful person. Russian tradition holds that an Upir is one who has denounced Jesus Christ, and as such, are therefore a servant of the Devil. Some sources also equate an Upir to a dragon while others describe it as an unclean corpse who has been possessed by a demon.  In the Elatomsk region of East-Central Russia, an Upir is described as a woman who had sold her soul to the Devil. 
In television fiction, Upirs played a major role in the Netflix original series Hemlock Grove. The series observed several details associated with the lore of the Upir, including the murder and consumption of children and family members. Season one of the series presented two characters who were Upir - Olivia Godfrey and her teenage son, Roman. Olivia's story was not fully revealed until the end of the season, but it is established that she is descended from Russian nobility. After having an unorthodox dalliance with a Gypsy commoner, Olivia became pregnant with child. Disgusted at her lot in life, she attempted to take her own life by severing a vestigial tail that she had grown. The show presents the notion that through the act of suicide (possibly limited to the act of bloodletting), an Upir awakens to their true potential and develops their vampire gifts. Olivia was shown to be very old and very powerful. She was very difficult to kill and could easily withstand injuries that would kill a normal human such as a bullet to the chest.
Hemlock Grove posits that an Upir woman may give birth to offspring who have the potential to become Upir themselves. Children born of an Upir who are enshrouded in a red caul harness the potential to become an Upir, while children born without it remain perfectly normal. Throughout her life, Olivia Godfrey sired many children, and always attempted to kill each one that was not born with the Caul. Two of her children are known to have survived. Roman was born with the Caul and so Olivia doted on him, awaiting the day that he would unlock his full potential. Another child, Shelley Godfrey, was not born an Upir and actually died when she was two-year-sold (presumably by Olivia's hands). Through the miracles of modern science however, and an unscrupulous scientist named Johann Pryce, Shelley was resurrected.
Olivia and Roman both possessed strong powers of hypnosis. Olivia actually used her power on Roman to manipulate him into impregnating his cousin, Letha Godfrey. Letha died during childbirth, but the baby survived. Olivia took the infant back to the family's mansion and attempted to force Roman to eat it. Disgusted at the revelation that he was the unwilling father of this child, he chose intead to take his own life. This however, did not kill Roman, but actually awakened his full potential. He turned against his mother, biting Olivia on the neck, drinking her blood and then bit out her tongue, which seemingly killed her.
Notes & Trivia
- On Hemlock Grove, both Peter Rumancek and his mother, Lynda Rumancek, immediately recognized Roman Godfrey as an Upir, but suspected that he was unaware of his true heritage.