Alpha 5 was the robotic assistant to the rangers during Mighty Morphin Power Rangers and Power Rangers Zeo. Alpha was an extremely important factor in the Power Rangers' battle against evil and acted as a secondary mentor to them, under his friend, the wise sage Zordon of Eltar. Alpha became famous for using the phrase "ay yi yi" in situations that involved any kind of emotion (most commonly panic). He worked in the Command Center most of the time, only getting out on a few occasions, and almost always obeyed every command and order that Zordon issued.
Alpha was built by King Lexian on the planet Edenoi. He is the second Alpha automaton to be in the service of Zordon, succeeding Alpha 4. Alpha was an advisor, mechanic, tech-wizard, and overall friend to the Power Rangers from Mighty Morphin leading up to Power Rangers: Turbo.
In one episode of Mighty Morphin Power Rangers, he became evil by the forceful insertion of a disk containing a computer virus that rapidly spread to his systems.
In the episode Teamwork, Alpha made an attempt at learning how to dance Zack's dancing/fighting style, hip hop kido. He didn't do very well, as he kept causing static in the communicators.
In the Green with Evil miniseries, Alpha was given a virus by the Green Ranger and ended up feeling weak. He was later turned off by the Green Ranger, but his back-up system kicked in. He then orders the computer to activate a force field around the Ranger.
In the episode Life's a Masquerade, Alpha's desire to "party" with the Rangers caused him to leave the Command Center temporarily and attend a costume party with them, using his robotic body as a "disguise" of sorts. At the end of the episode, he won first prize for his "costume", and had a lot of ladies flirting with him. In another episode, Alpha again teleported down to a Halloween party in Angel Grove, but we never see him go there.
In Power Rangers: Turbo, Alpha 5 left with Zordon to the planet Eltar and was replaced by Alpha 6. His last appearance is in Passing the Torch but he is in his old robot armor/suit. He's not been seen or heard of since. Wild Force writer Amit Bhaumik has said that he takes the view that Alpha was slaughtered in the battle against Dark Specter, but there is no canonical confirmation.
Alpha 5 was dearly loved by the Rangers and Zordon.
Alpha 5 was voiced by Richard Steven Horvitz. As a homage to Alpha 5, the character Alpha 7 that appears in the anniversary special Forever Red has the same voice.