Aerodactyl is a reptilian, bipedal prehistoric Pokémon that resembles a pterosaur with several draconic features. It has small sharply pointed ears, narrow dark green eyes, a ridged snout, a gaping mouth, and a strong lower jaw full of serrated fangs. Its body is covered in light blue-gray skin and it has large, violet membranous wings. The clawed hands at the end of each wing allow it to grasp objects. There is a hump-like ridge with a spike on its back, and it has a strong tail with an arrow-shaped tip. Its talon-like feet have two toes in front and one in the back, and are capable of scooping up and tightly clutching its prey in flight.
Aerodactyl's serrated saw-like fangs and ferocious attitude were very imposing in its time. Its fangs can rip out throats and tear through the skin of any Pokémon to pieces, even Steel-type Pokémon. By spreading its wings, Aerodactyl is believed to have flown by gliding through the skies, freely letting out its high-pitched cries. However, it is slow to walk on land. It liked to nest in the mountains, where it enjoyed both safety and seclusion. Aerodactyl lived in prehistoric times, and was theorized to become extinct thanks to a giant meteor impact. It was restored in modern times using genetic material extracted from amber; some casualties occurred during these attempts. Even still, this restoration is not considered perfect.
As Mega Aerodactyl, its eyes turn bright green and parts of its body turn to stone, which some researchers believe to be its original appearance before fossilization. It grows larger and sprouts jagged black spiky rocks all over its body: five spikes at the wrist joint of each wing replacing its hands, three small spikes along its tail, one spike on each ear, and a long spike on its chin. The spike on its back and its rear talons have also become black and stony. Rocky plates cover its eyebrows and the corners of its jaw. Similar stone ornaments are present on its chest on its torso: two small ridges flanking a longer ridge.
The power of Mega Evolution allows some of Aerodactyl's dormant genes to reawaken. The rocks on Mega Aerodactyl's body are harder than diamond. Because of the burden of Mega Evolution, Mega Aerodactyl is fiercer and more irritable than before. As a result, Mega Aerodactyl attacks anything that moves.
In Pokémon Heroes: Latios & Latias, an Aerodactyl was resurrected from a fossil alongside a giant Kabutops by Annie and Oakley. In the English dub, it was described as having been used by an evil Trainer to torment the civilians of Alto Mare but was drowned when a Latios brought water to the city. It was ordered to chase after Ash and Latias. It had blank, yellow-tinted eyes with no pupils and a thick black outline.
In Holy Moltres, an Aerodactyl appears as a silhouette in Blaine's fantasy of what the Old Amber would turn into when it would be revived. Later, Red obtains an Aerodactyl from a resurrected piece of Old Amber which he revives in Holy Moltres and names him Aero. He has since then used him extensively for aerial transportation and combat.
Lance has his own Aerodactyl that he also uses for aerial transportation and combat which first appeared in Extricated from Exeggutor. He also owns multiple other Aerodactyl which were used in his Dragon-type army that were used to attack the mainlands of Kanto. They first appeared in Playing Horsea.
This is likely due to pterosaurs being known as "winged dragons" (翼竜 yokuryū) in Japanese, further explaining why it is called a "dragon" by an old man in Pewter Museum of Science in Generations I, III, and VII, as well as suggesting why its appearance is influenced by that of wyverns.
Mega Aerodactyl has the highest base Speed stat of all Rock-type Pokémon.
Aerodactyl is the first Fossil Pokémon to have its Egg shown in the anime.
Aerodactyl's design is mostly based on rhamphorhynchids, a family of toothed pterosaurs that lived in the Jurassic period. However, its pointed wings, spaded tail, and robust jaws also give it the resemblance of a dragon, specifically wyverns.
The rocks that appear on Mega Aerodactyl's body is a reference to atavism whereby an ancestral genetic trait reappears after having been lost through evolutionary change in previous generations. The rock on Mega Aerodactyl's chin is similar to goatee.