The Spider-Slayers are a series of killer robots from Marvel Comics that were created specifically to hunt and kill Spider-Man. The original Spider-Slayers were made by robotics expert and scientist Spencer Smythe, who was funded by J. Jonah Jameson. Smythe's first few models were clunky, yet dangerous humanoid robots that had verious functions designed to stop Spider-Man's powers. These were all easily defeated by the resourceful web-slinger, and Smythe continued to make newer and more improved versions, these having an insectoid-type shape to keep up with Spider-Man.
After Spencer died from radiation poisoning, his son Alistair took the reigns and sought revenge on Spider-Man. His versions of the Spider-Slayers were powerful, terrifying monster-robots that gave Spidey a real challenge.
The Spider-Slayers also appeared in Spider-Man: The Animated Series and came in three versions, all designed to look like various arachnids.