Fierce cosplayers are always to be expected at the annual Comic-Con in San Diego, but who would have thought Liev Schreiber and Naomi Watts' son would take things to a whole other level.

The actors' 8-year-old son Kai absolutely slayed as Harley Quinn in an amazing costume, eliciting praises from every corner of the internet.

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Schreiber was in attendance to talk all things My Little Pony: The Movie, a reboot of the 1980s cartoon, while Watts promoted Twin Peaks at the events. Based on the reactions from folks on the internet, their son was the only star of the family over the weekend.

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Schreiber, who donned a Batman mask, also took time to pose for some pics with his kids from Entertainment Tonight's Comic-Con photo booth. Schreiber's 9-year-old son Sasha also donned a costume, choosing to dress as a Jedi.

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Dad of the year, truly.