Cobra d'água literally translates to "water snake". In Brazilian funk slang, however, it's used as a boast describing someone who is slick, fast, and impossible to catch or beat, slipping past rivals the way a water snake slides through water.
In the song, the chant "Nós é cobra d'água" (We are water snakes) is repeated as a confident, playful declaration that the singers are too clever and quick for anyone to outsmart them.
Mc Jacaré's "Cobra D'água" is a boastful track where the artist confidently asserts his success with women, contrasting himself with others who only observe from a distance. He sings about people scrolling through social media, looking at stories and photos, while he's actually with the person they admire. He puts it pretty bluntly: "Enquanto vocês curtem stories Eu amasso ela Vejo ela pelada e vocês só veem a tela" [While you guys like stories, I'm with her, I see her naked and you only see the screen].
The song's title, "Cobra D'água" (water snake), is used to describe those who are just spectators. Mc Jacaré explains that his grandfather told him, "quem não faz vê os outros fazendo" [he who doesn't do, watches others doing]. He sees himself as the one taking action, enjoying life, while others are just watching. He repeats, "Vocês é cobra d'água Eu que como tudo" [You are water snakes, I'm the one who eats everything], really driving home the point that he's the one experiencing things firsthand.