Will Arnett’s biggest fan is an 8-year-old named Ellie.

On Monday’s “Jimmy Kimmel Live!”, the “Murderville” star got a surprise when the host virtually introduced him to superfan Ellie Palumbo, who went viral for her Will Arnett-themed birthday party.

READ MORE: Netflix Drops Trailer For Will Arnett’s Star-Studded ‘Murderville’ Crime Comedy Series

“Listen, I’m sorry, this is a little belated, but happy birthday,” Arnett said, before asking, “How did it go? We people really puzzled about your birthday?”

“Yeah,” Ellie told him. “People thought you were my dad.”

Arnett responded, “Well you know what, that’s a compliment.”

“It could also be a paternity suit, we don’t know,” Kimmel joked.

READ MORE: Will Arnett Fills In For Jason Bateman As A Last-Minute Guest On ‘Kimmel’

Asked if her friends like Arnett, too, Ellie said, “Some people don’t know about him,” to which the actor joked, “Well you know how they will know about me, Ellie? You’re gonna do this every year for the rest of your life. And I’m coming down there.”

Elli also revealed that she collects Will Arnett memorabilia, like a travel mug with his face on it, multiple Will Arnett notebooks.

Asked if she’s also a fan of Jason Bateman, Ellie shook her head, to which Arnett laughed, “Good for you!”