Pack (canine)
Animals which typically predominate over others are associated with the term "alpha". Among pack-living wolves, alpha wolves are the genetic parents of most cubs in the pack. Such access to mating females creates strong selective pressure for intra-sex competition.
List of Ice Age characters
Steffie is a teenager woolly mammoth who is the alpha girl of the Valley's popular crew. Her friends, Katie and Meghan, are always in agreement with her. She does all that she can to keep any other girls away from Ethan, which is why she dislikes and insults Peaches. She is the sassy leader of the Brat Pack. Although she is rude and unkind, she can be sweet when she is with Ethan; when Louis and Peaches show their bravery fighting Gutt, she begins to warm up to them. 
Katie and Meghan are teenage woolly mammoths who are two of the first-rate members of the Valley's popular crew. Katie and Meghan are always in agreement with what Steffie says, and they do everything that Steffie does or asks. To Steffie, Katie is likely more important than Meghan, as they sometimes leave Meghan alone. Katie is known as the gossip girl of the Brat Pack.