Hyenas are dog-like creatures found in Earth and Narnia and they are maybe part of Jadis's Army in The Lion, the Witch and the Wardrobe. They never appeared in Lewis' Workshop.
Hyenas appeared before Aslan is about to die. Like in The Lion King, hyenas are villains in the movie, working for Jadis the White Witch instead of Scar. When Aslan is about to go to the Stone Table, various hyenas in the crowd. One starts to bite Aslan's foot. The hyenas were never seen again, but later, it is debatable when they ran away, or join the Old Narnians, and fight against the Telmarines.