Alph

"You have done well, Earthling, but I shall now have to exterminate you all for taking so long! ... ... ... Er, have you kids seen my laser anywhere? ... ... ... Ah, it must be on the ship. Your race is spared for now, Earthling."

- Alph

Alph, also known as simply Alien Dad, is an Alien who lives inside an U.F.O. alongside Beti, Gammo, and his three children, Alphette, Betette and Gamette. He is named after the Greek letter "α," which is pronounced "alpha."

Banjo-Tooie
In Banjo-Tooie, Alph can initially be found inside his UFO alongside Beti and Gammo in Jolly Roger's Lagoon. They explain that they crashed into the water, and the drive unit of their ship ran out of fuel. As it is powered by crystallized ice, Kazooie needs to fire Ice Eggs in all four crystals of the UFO to power it and allow the aliens to leave, heading to the Icy Side of Hailfire Peaks where their children landed and leaving a Jiggy behind.

In the Icy Side of Hailfire Peaks, Alph opens the ship's door to "enable manual viewing," but ends up falling off and dying. Once Mumbo Jumbo revives him with a Mumbo Pad, he explains what happened to the kids and uses his "alien signal" to make them appear, asking for them to be rescued so the aliens can depart from Earth. Once Alphette, Betette and Gamette have been rescued, Alph prepares to exterminate all "Earthlings" for having taken too long, but as he can't find his laser, he decides to spare them, entering the UFO and leaving another Jiggy behind.

Banjo-Kazooie: Nuts & Bolts
In Banjo-Kazooie: Nuts & Bolts, Alph and his family are vaguely mentioned in Banjoland by an Infopost in the description of the U.F.O. exhibit. It mentions how, in Banjo-Tooie, the ship carried the aliens.

Some aliens also appear frozen in cryogenic capsules in the Terrarium of Terror, although it is unspecified whether or not they are the same ones from Banjo-Tooie.