Skrulls are a fictional alien race in the Marvel Comics universe, known for their ability to shapeshift into other beings. They first appeared in Fantastic Four #2 in 1962 and are often depicted as adversaries of the Avengers and the Fantastic Four. Skrulls have green skin, pointed ears, and can mimic the appearance and voice of any person they encounter. In the comics, the Skrulls are part of a larger intergalactic conflict, often clashing with other alien races, including the Kree. Their shapeshifting abilities make them skilled spies, leading to storylines involving infiltration and deception. The Skrulls have gained popularity through various adaptations, including the Marvel Cinematic Universe.