Screeech is a falcon owned by Skeletor, used for aerial attacks agains the Heroic Warriors. The character was initially a natural counterpart to Zoar, but while Zoar's role expanded as the franchise evolved, Screeech has largely remained a simple bird and is relatively obscure in Masters of the Universe fiction.
Although Zoar was quickly developed from a mere falcon into the divine messenger of the Goddess, and finally into the alternate form of the Sorceress herself, Screeech has usually been nothing more than a large falcon. Like Panthor it is typically not given the means to speak, and servers little purpose in stories except to divebomb the heroes with its considerable arsenal. In He-Man and the Memory Stone, features Screeech being sent out by Skeletor to drop an arsenal of deadly bombs on He-Man.
The Sunbird Legacy depicts Screeech as an alternate form of Evil-Lyn, paralleling (intentionally or not) the relationship between the Sorceress and Zoar. However, this concept was not used elsewhere in the franchise.
The character's portrayal on He-Man and the Masters of the Universe, by Filmation, is completely different from all other media. Here Screeech is a purely robotic falcon, with a large computer screen on its chest. In its first appearance, "Fraidy Cat," Screeech is noticeably out of scale with actual falcons, facilitating the plot point that Cringer must valiantly leap onto its back to escape Snake Mountain and warn He-Man of its impending attack.
Screeech later appears in "Visitors from Earth" and "The Toy Maker". The former of these features Screeech being used in an attack on Castle Grayskull, to desposit an explosive missile beneath the castle's jaw bridge.
The original Masters of the Universe toy line released Screeech both as a standalone figure and as part of a two-pack with Evil-Lyn (mirroring the Teela/Zoar two-pack). Little more than a repaint of Zoar, Screech came with a harness armed with missiles and a perch. The figure's curved toes were shaped in such a way that it could not stand freely, except on the perch or a person's finger. Like Zoar, Screech's thigh contains a button that pushes on its flexible wing assembly, to cause the figure's wings to beat.
The same model was also used in 1972 for the bald eagle from the Big Jim toy line; which explains the 1972 date on both Zoar and Screech.