Alien lead characters often have unique physical features. For instance, they might have multiple eyes like some insect - like aliens in various movies. They also tend to have different languages or ways of communication, which can range from telepathy to complex clicking sounds. Their cultures can be very different from human cultures, with different social structures and values.
Many alien lead characters possess extraordinary abilities. Some can fly without the aid of any technology, like certain winged aliens. Their intelligence levels can vary greatly. Some are super - intelligent, like the Time Lords in 'Doctor Who', while others might be more instinct - driven like the Xenomorphs. Their appearance may be adapted to their home planet's environment. For example, if their planet has a high - gravity environment, they might be short and stocky. In terms of behavior, they can be either peaceful, like the Ewoks in 'Star Wars', or extremely aggressive like the Klingons in the same franchise. They also may have different moral and ethical codes compared to humans, which can lead to interesting storylines when they interact with human characters.