Henry Winkler, Maya Rudoph Henry Winkler, Maya Rudoph

The Fonz is sporting a sweet ponytail in this first look at former Happy Days star Henry Winkler guest starring on this Thursday's Up All Night (9:30/8:30c on NBC). In the episode, titled "Daddy Daughter Time," Henry appears as Ava's father, Robert Alexander, a beloved children's book author. Ava (Maya Rudolph) is none too pleased that dad's brought along his family, who are more interested in meeting celebrities at Ava's work place than spending time with her alone.

Among the celebs the star-struck family has their eyes on is Sharon Osbourne, guest starring as a version of herself whom Ava has long considered a rival. Reagan (Christina Applegate) also starts to feel the heat at the studio when husband Chris (Will Arnett) lands a segment on The Ava Show.

Here's an exclusive clip from the episode:



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