The phrase comes from spoken German dialect, where Vadda is an informal pronunciation of Vater, meaning father, and the whole line plays on stating the obvious about a son resembling his parent. Short dialect sayings like this spread online as WhatsApp audios and soundboard clips because the pronunciation alone sounds funny even to listeners who do not speak the dialect fluently. It stays popular as a quick family joke, reused in meme edits and reaction videos whenever resemblance, pride or stubborn dad energy is the point of the scene.