Alf

Plot (Spoilers!)
ALF is an alien from the planet Melmac who follows a radio signal that leads to earth and he lands in the garage in California to meet the family known as the Tanners. The Tanners are a middle-classed family in the suburbs of San Fernando Valley, California. In the family the members are Willie, his wife Kate, their daughter Lynn, their son Brian, and their pet cat Lucky.

Unsure what to do, the family takes ALF into their home to conceal them from the ATF (Alien Task Force, part of the U.S Military) so that they don't take him, and to hide him from the nosy neighbors until he can repair his spacecraft and leave Earth. Eventually, its shown that ALF's planet, Melmac has exploded due to a nuclear war outbreak. In the first episode, "Pennsylvania 6-5000" ALF attempts to convince the President to stop the nuclear program because ALF fears that Earth will suffer the same fate as Melmac. Due to ALF choosing his words poorly, the President and the national security send the FBI after Willie and arrest him. ALF left Melmac because he joined the Melmac Orbit Guard. Although he is homeless, he is not the last of his kind. He then becomes a member of the family and his feelings of boredom, loneliness, and despair add an extra burden to the Tanners. Despite it being hard taking care of ALF, they've learned quickly to love him. Although that the show is mostly for comedic purposed, the show teaches a bit about real space topics. Each episode in the show is about ALF being taught about Earth and similar space topics and him learning about friendships outside of the Tanner family such as: Willies brother, Neal, Kate's widowed mother, Dorothy, and plenty more.