Pagan Gods (and Goddesses) are many and various, from all corners of the globe, all different shapes, sizes and manifestations. To try to cover more than a few would be a mammoth undertaking, but there are some attributes that appear regularly among different pantheons.
On the whole, pagan deity have very human attributes: they usually appear as amplified versions of mortals. When they love, it is more passionate; when they fight it is more bloody. This is possibly due to one over-arching reason: deity are how our ancestors tried to make sense of their own existence, their lives and the things that happened around them. Their only point of reference was themselves, but they understood that they could not create the sound of thunder or raise mountains from the sea or make a seemingly healthy person fall down dead.
Our ancestors had to explain these occurrences somehow, so the deity became personified. The Gods and Goddesses were given names; stories began to evolve about them, telling of how they looked, how they behaved and how they lived with others of their kind. And because most cultures have similar societal constructs, the attributes given to the deity also emerged as similar across continents.
Unlike the Christian God, most pagan deity are not omnipotent. They do not have the ability to be the biggest, best or strongest all the time. They are tested regularly, by all manner of things (monsters, demons, other deity) and do not always win. They often have learning still to do or skills to hone, and despite usually existing in a land of plenty and not having to face the prospect of starvation unlike their mortal believers, they do still have trials and quests to achieve. Some also have defects such as blindness or deafness, and they are not eternal beings: some actually die.
Pagan gods are generally also not omniscient. There would be no intrigue in the thousands of stories told of them if they were. They may have extraordinary powers but few have a huge wealth of knowledge and often only learn things by overhearing others' conversations or by slight of hand.
There is generally something about a pagan deity that makes them unusual, even among other deity. This could be a possession, such as a golden apple, a sacred spring, or a particular skill, or it could be the way they look (astonishingly beautiful or hideously ugly), or possibly it could be the way they interact with others such as always being comical, deceitful, helpful, wise etc Most will have at least one well known (by their followers) story or tale in which they feature, which often also contains a lesson or moral or at the very least something the listeners can relate to in their everyday lives.
Some deity have physical attributes that do not change with every retelling such as colour of hair or height, but often their clothing or descriptions are secondary and can be embellished according to the whim of the storyteller. Until recent times, there were few images available of pagan deity, particularly in the western world. Crude statues have aways existed, but detailed artworks are rare. This suggests that it was less important to the followers to have a precise pictorial representation of their deity than to know their character traits.
Finally, pagan deity are powerful, but often only within their own sphere of reference. Those associated with the weather for example, have little power over humans. Those who are violent on the field of battle, would not be called upon to aid a woman in childbirth. They form part of a community structure recognised by their followers, and each take a particular responsibility for the important functions of that community.