Scream was one of many symbiotes.
History in the comics
Much of Donna Diego's early life is unknown. Donna had a history of psychotic episodes, but despite this she passed a background check and became a security guard for the Life Foundation. As part of their program to create a super-powered security force, the Life Foundation scientist kidnapped Venom. They removed his symbiote's "seeds," hatched them and merged the resulting creatures with five of their most skilled and trusted employees. One of those employees was Donna Diego.
While testing her new powers, Diego (now calling herself Scream) attacked a mall in Salinas, California. She encountered Spider-Man, who was looking for Eddie Brock and fled back to the Life Foundation's base in the Mojave Desert. Spider-Man stowed away on her hovercraft and released Brock. Scream and the other symbiotes fought Spider-Man and Venom and apparently died in an explosion.
However, Scream would return and attempt to capture Venom so that he could teach her and the other symbiotes how to control their power. However, this failed.
Venom later started to hunt down the symbiotes and killed Scream.
Scream posesses all the powers of Venom which include wall crawling, super strength, agility, and she can fire webbing.
Scream can extend her hair-like tendrils to lash at or encircle her foes.
Scream could create a knife made out of sonic energy.