a fake/false friend
Adriana é uma amiga da onça, diz que gosta de mim, mas está falando mal de mim nas redes sociais!
Adriana is a false friend, she says she likes me, but she's talking bad about me on social media!
The character 'Amigo da Onça' was created in 1943 by the cartoonist Péricles de Andrade Maranhão for the Rio magazine O Cruzeiro. The strip starred a man who delighted in delivering cruel punchlines to his best friend at the worst possible moments.
Source: Wikipédia — O Amigo da Onça.
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