Since their introduction to the Marvel Universe, symbiotes have produced some of the strangest, most mind-bending stories of all time. Without a doubt, "The Nativity" arc (by Mike Costa and Mark Bagley) is among Venom's most unusual stories, featuring the alien symbiote becoming "pregnant" (while Eddie Brock was his host) and giving birth to the Sleeper symbiote. As seen in the pages of 2018's Venom #164, Eddie had a nightmare about the alien's symbiote children. He awoke screaming before succumbing to sudden vomiting, much like an expectant parent would during their first trimester.
Source：https://www.cbr.com/how-venom-impregnated-eddie-brock/
