Back while the cast of “Suicide Squad” was promoting the 2016 film, a story circulated that Jared Leto was so deeply into character as the joker that he pranked co-star Margot Robbie by giving her a gift box containing a live rat.

Viola Davis, who also starred in the film, spoke with Vogue for a profile on Robbie to reveal that story was 100-per-cent true.

According to Davis, the cast had gathered for a rehearsal when everyone but Robbie realized that Leto was about to prank her.

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“I was saying loudly, ‘Don’t open the box!’ I was halfway out the door when she opened the box,” Davis told the magazine.

When Robbie ignored that advice, she opened the box “and saw the biggest black rat you could imagine.”

It was Robbie did next, Davis admitted, that really surprised her. Then… she cooed at it. No fear. Open. Receptive. Full of joy.”