The phrase tio tranquilo y chill de cojones mixes Spanish slang with the English word chill, which is part of why it travels well in Spanish speaking meme spaces. Clips like this spread through short reaction videos and soundboards where a single confident line can stand in for a whole mood. It stays popular because it needs no context, works in group chats as a voice note style reply, and instantly signals the poster is relaxed, joking and not taking the situation seriously at all.