| This is starting to sound like a bad comic book plot|
This character is non-canon to Spider-Man: The Animated Series.
The Alien Spider Slayer was created by Alistair Smythe possibly by using alien technology. The Alien Spider Slayer then fought Spider-Man. After his defeat the Alien Spider Slayer was taken to Ravencroft Prison.
Escape from Ravencroft
Spider-Man once again defeated Alien Spider Slayer and he was sent back to prison.
The Alien Spider Slayer is extremely fast and agile. It also had a large amount of spikes and claws sprouting from it's body.
In the comics
An alien-like robot, the Mark X was the first Spider Slayer to attack Spider-Man in the "Invasion of the Spider-Slayers" saga. Attacking Spider-Man while he was swinging through town, the Mark X was close to disemboweling Spider-Man until a nearby construction worker managed to decapitate it using a jackhammer. Alistair later rebuilt the Mark X to be used in his Spider-Slayer army, which was destroyed by Spider-Man.
Mark X was extremely fast and agile and had a large amount of spikes and claws protruding from its body.