Zeta's Eagles are a group of eagles who agreed to ally with Zeta to accomplish her dream of building a three-island resort by demolishing Bird Island and Piggy Island, after being spurned by her lover Mighty Eagle just before he was going to marry her. Many of them worked to construct, program or protect her superweapon on Eagle Island, which she plans to use to accomplish her goals.
After being spurned by Mighty Eagle, Zeta retreated to an arctic island called Eagle Island and began constructing an arctic resort with a group of eagles, after gathering riches and technological expertise in secret. Dissatisfied with being on just one island, she then pursued a plan to destroy two neighboring islands, Bird Island and Piggy Island, with a superweapon that she and her eagles constructed. When she finally completed her weapon and fired it for the first known time on those two islands, she inadvertently ended the Great Egg War between the Birds and Pigs, drawing them into an alliance to stop her before she could wipe them out.
Knowing that her weapon was not safe from such adversary, Zeta ensured that her eagles would keep the weapon under guard, armed with ice spears. Most of them stayed inside the base to protect the weapon, with only a few eagles stationed to watch for intruders outside her base, who failed to notice the alliance's special forces beginning their mission to destroy the weapon a few days after it was formed. Two eagles, Carl and Jerry were assigned to guard what appeared to be the base's main entrance, but did not anticipate that much of the special forces team disguising themselves as Harvey, a mechanical decoy eagle, to sneak in.
The special forces team controlling Harvey steal a key card from Brad in one of the base's bathrooms, knocking him out with it, to enter the main cannon chamber. The team then distracts all the eagle guards inside with a break dance, until Chuck notices that Hank, one of the toughest Eagles in Zeta's guard squad have subdued and captured Red and Silver after the former made a prior botched attempt to disable the cannon. Out of desperation, he accidentally destroys the Harvey costume, forcing the special forces to retreat and lock themselves in a room to regroup. The dancing eagles somehow got carried away with the entertainment Harvey offered so that they ended up not noticing the real intruders as they escaped detection.
Eventually, the eagles returned to duty, seeing no threat, until Zeta announced that her cannon was finally ready to launch a barrage of emulsified lava-ice balls for maximum destruction in ten minutes, rallying them to remind them that her vision with them was close at hand. By that time, the Bird-Pig elite forces reunite with Red and Silver just as they freed themselves from captivity and put together a renewed plan to stop Zeta.