The Pilgrims played at least three roles for Native Americans in their region. They played somewhat different roles for different native peoples.
When the Pilgrims came, they were soon used by Native American groups to further their own ends. The Indians could see that the Pilgrims might be useful as allies and therefore tried to cultivate friendships with them. Therefore, the Pilgrims came to play the role of allies to some Native Americans.
The flip side of this is that the Pilgrims became a real menace to some Native American groups. This can be seen most clearly in what is now called the Pequot War. This was a war between Native American groups in the 1630s. The Pilgrims took one side in the war and helped for example, to massacre Pequot people at a village on the Mystic River. Thus, the Pilgrims were direct enemies of some Native Americans.
Finally, the Pilgrims played the role of destroyers of the Indian way of life. This was done both purposefully and inadvertently. The Pilgrims purposely tried to convert the Indians to Christianity. They purposely took some Indian lands. On the other hand, they were not trying to destroy the Indian way of life when they started to trade with them. Even so, their goods changed the Indian economy and society. Their diseases also killed off many Indians. In these ways, they changed the Indians’ ways of life drastically.
Thus, the Pilgrims played various roles with relation to the Native Americans.