Deke Cavez is young, tall and slight, and "fast enough to run down a hoverbike on foot". His uncle taught him how to hunt.
A good leader, Cavez's youth and inexperience has sometimes caused him to make mistakes during combat. He is also afraid of the protoss.
Cavez, the youngest member of Raynor's immediate team to land on Char, provided assistance in scouting and combat against the zerg. During the first battle against Sarah Kerrigan, Cavez was injured, but he was more concerned with the (comparatively mild) injuries suffered by his commander, Jim Raynor.
When Raynor's shuttles were stolen, the team met around the crash of a shuttle. There, Raynor granted him a leadership role. Back at base camp, he was formally promoted to lieutenant, becoming Raynor's executive officer alongside Lieutenant Abernathy. One of Cavez's first tasks was to set up guard duty; he chose five of the wounded troopers to do so, giving them important roles without requiring them to move much. He also had soldiers who knew how to hunt set up hunting snares; Cavez had been a hunter in his civilian life.
Cavez was nervous about the protoss who had also arrived on Char, and especially didn't like "teaming up with aliens" when Raynor proposed it. Raynor left to meet up with the protoss and propose an alliance anyway, but while he was gone the Raiders were attacked by the zerg. Cavez felt he didn't need to wear his marine armor, as he believed the other troopers needed it more. During the battle, Lieutenant Abernathy was wounded by a zerg, which Cavez shot in its throat. Cavez believed she was dead, but in fact her armor had simply locked her down. Raynor and the protoss arrived near the end of the battle, defeating the zerg. Raynor, noticing Cavez's lack of armor, told him he needed it more than the lower-ranking troopers, as without it, he was a liability. Cavez was able to lead Raynor to Abernathy's "body"; Raynor knew that her armor had automatically locked her down and rescued her.
Following the attack, Raynor's Raiders had to move. A shuddering Cavez suggested splitting from the protoss, but Raynor disagreed; he knew Kerrigan was hunting his forces along with the protoss.
Following another battle between the Raynor's Raiders/protoss alliance and the zerg, Cavez agreed that allying with the protoss wasn't so bad. Still, his xenophobia resurfaced when he saw how much time Raynor was spending with the protoss leaders, Tassadar and Zeratul.