How did Gabe Ugliano lie on Percy?

Gabe Ugliano lied to Percy by spreading false rumors about him, particularly suggesting that Percy was trouble and a danger to others. This manipulation was part of Gabe's larger character of being deceitful and self-serving, as he sought to undermine Percy and maintain control over his own environment. Gabe's actions reflect his desire to protect his own interests, even at the expense of others' reputations.