Taylor Swift showed off her wild side by donning a tiger-striped catsuit for Dianna Agron's circus-themed birthday party over the weekend (28-29Apr12).

The Glee actress turns 26 on Monday (30Apr12), and she rounded up her closest friends for a celebration in Los Angeles on Saturday (28Apr12).

Dianna Agron donned a trapeze artist costume to party the night away, while her superstar singer pal Taylor Swift wore a tight, striped outfit and cat ears in accordance with the circus theme.

Taylor Swift showed off a series of snaps on Twitter.com of her and Dianna Agron posing with friends, and wrote, "The most magical night at Dianna Agron's circus themed birthday party!"