This research has aimed to test whether "darker" humor-related dispositions can contribute to the prediction of online trolling over and above the influence of dark personality traits. A total of 201 participants (50.7% women) gave responses to dark personality, humor, and online trolling measures. Our results corroborated the one-factor structure of the Spanish version of the Global Assessment of Internet Trolling (S-GAIT) and replicated online trolling's robust associations with increased psychopathy, sadism, and Machiavellianism. Online trolling also correlated with an elevated use of aggressive and self-defeating humor styles, as well as with heightened expressions of the joy in laughing at others (i.e. katagelasticism) and the joy of being laughed at (i.e., gelotophilia). When applying hierarchical regressions to eliminate the redundancy among these traits, we found that katagelasticism incrementally explained variance (Delta R-2 = 10.2%) in online trolling even after accounting for gender and the Dark Tetrad (i.e., male gender and high psychopathy as main predictors: Delta R-2 = 27.3%). A subsequent moderation analysis indicated that higher levels of psychopathy was related to a greater engagement in trolling behavior among those high in katagelasticism. This research provides empirical evidence that contributes to elucidate the "dark" humorous nature of this pervasive antisocial online behavior.