Angeal Copies are clones of Angeal Hewley in Crisis Core -Final Fantasy VII-. They are similar in nature to Genesis Copies and Sephiroth Clones. Unlike the other two, they are typically monsters, but with a unique feature: they have Angeal's face grafted onto their bodies. The Copies are able to recognize each other in a limited sense.
According to the Crisis Core Complete Guide creating Copies happens by transplanting the cells of a G-Type SOLDIER into a physically strong subject, copying the donor's abilities, appearance, and characteristics onto the subject. However it does not always yield perfect results, and differences in appearance and ability may arise based on the subject's latent potential. The reason the Genesis and Angeal Copies seem weaker than their originals is due to the subject's latent potential being inferior to the original's, and are unable to fully utilize the abilities they receive.
The influence of the copying process extends to the subject's mind, and if the subject's will is weak their will is completely taken over by that of the cell donor and leads to a breakdown of their sense of self. This is what happens to the SOLDIER operatives who become Genesis Copies. If the subject is strong willed, they can maintain their identity while still being influenced by the will of the cell donor, such as Lazard as an Angeal Copy.
Since Genesis Rhapsodos was a "failure" in terms of similarity to Jenova, his clones are limited to only humans. However, Angeal was the most perfect creation of Project G, and thus can pass on his genes to any creature, be them human or not. He can also take on the traits of his own Copies, which he used to transform himself into the hideous chimera, Angeal Penance.
The only known human Angeal Copy is Lazard Deusericus, who was transformed into an Angeal Copy late in the game. After changing, Lazard took on Angeal's physical features, including Angeal's white wings. Despite Angeal's supposed "perfection", Lazard became subject to the same degradation as Genesis and his brand of Copies. Another Angeal Copy was a metallic wolf that helps Angeal's friend Zack Fair protect Aerith at the Sector 5 Church. This copy is special in that it had its own wings. Both die of the degradation at the end of the game, apparently ending Angeal's genetic memory on the Planet.
Furthermore, the Crisis Core Complete Guide reveals that Angeal Copies have an ability to call to one another, such as how Lazard is able to coax the wolf-like Copy in Aerith's church to come help him in Banora.