The Desert wolves are sometimes seen with their pack leader, a Shade Wolf, Roc.
They are significant to the plot of the main storyline in NieR Replicant,
Possible item drops upon killing a Wolf:
Wolves Major Events
When NieR is invited back to Facade to witness the King of Facade's wedding, the celebration was cut short by an intruding pack of wolves who unfortunately took the life of the Queen. The King sought out revenge with the help of NieR, taking their fight directly to the den of the wolves in the desert.
NieR joins the King of Facade with his Men of the Mask and locate the den of the wolves and begin a boss action sequence against the pack and their pack leader, a Shade wolf named Roc. Once he is defeated, the King of Facade properly mourns the Queen.