Scrad isn't really very bright; he doesn't quickly realize when people are talking to him, or telling him what to do. This greatly irritates and/or annoys Serleena now and then.
Scrad has another head coming out of his backpack (Charlie), although it is the same head, and just a long neck. Scrad is basically a moron, not realizing when people are talking to him, or telling him what to do. Serleena knows Scrad and Charlie, as she comes right to him when she came to Earth. They work together in the infiltration of the Men in Black Headquarters.
Role in the film
Scrad and Charlie first appear when Serleena appears at their apartment. At first, they don't recognize, but when an annoyed Serleena plugged her tentacle into Scrad's ears, they finally caught up to her. They later get involved in Serleena's takeover of the MiB HQ (by faking a heart attack) and the release of the alien criminals in exchange for their cooperation.
Scrad and Charlie are then assigned to track down Agent J and K while the latter is trying to restore the former's memories about the Light of Zartha. They followed down to Jack Jeeb's workshop, where several inmates try to kill J. However, K defeats the inmates after getting his memory restored, forcing Scrad and Charlie to escape back to MiB HQ. When Serleena learns that a pizza delivery girl named Laura Vasquez is the Light of Zartha, she sends over Scrad and Charlie to kidnap her.
It is unknown what happened to Scard and Charlie following Serleena's death at the hands of Agents J and K.
Scrad: W-Who are you, and how'd you get in here? Charlie: You like egg salad?
Midway through Men in Black II, Scrad and Charlie just seemingly disappear without explanation. It could be so that because Charlie felt sick, they quit working for Serleena or K killed them in a scene that was cut.