Ryan Reynolds’ ‘Step Brothers’ Themed Birthday Tribute To Will Ferrell

Ryan Reynolds sure knows how to wish his fellow funnyman a happy birthday. Over the weekend, Reynolds shared a birthday message via TikTok for his Spirited co-star, Will Ferrell.

Ferrell, who will star opposite Reynolds in the Apple TV film of the musical reimagining of the Charles Dickens' classic, A Christmas Carol, turned 55 on Saturday (July 16).

The Deadpool star's clip is soundtracked by “Por Ti Volaré," the Spanish version of Andrea Bocelli’s famous track “Con te Partiró." The song was famously used in Ferrell's 2008 hit comedy Step Brothers, in which he starred alongside John C. Reilly. In one of the many iconic moments of the film, Ferrell’s character, Brennan, performs a triumphant rendition of “Por Ti Volaré” during the Catalina f---ing Wine Mixer.

To celebrate Ferrell’s birthday, Reynolds shared his own variation on the moment. Unlike in the film, Reynolds stays silent and looks too nervous to give it a crack at singing along to the song. The actor – wearing a grey T-shirt, hat and glasses – appears awkward and confused over when to chime in. The TikTok video also included the text: “Happy birthday, Will Ferrell!!!”

There are over seven billion people alive on this Earth. So the possibility of a doppelgänger walking around looking exactly like you is highly probable. A doppelgänger is defined as a biologically unrelated look-alike, or a double, of a living person. In fiction and mythology, a doppelgänger is usually seen as a harbinger of bad luck or seen as an evil twin. Research has found that people who are "true" look-alikes have more similar genes than people who don't feature a resemblance to one another.

Doppelgängers have made their way into modern literature, films, and television. Some of our favorite examples include the series finale of Twin Peaks. In the chilling scene, Special Agent Dale Cooper encounters a variety of doppelgängers in the Black Lodge, one of whom is a malevolent version of himself. His doppelganger switches places with him at the conclusion of the 1991 finale, trapping the original in the Black Lodge. In the show's sequel, Twin Peaks: The Return, three different doppelgängers are dispatched from the Black Lodge.

Christopher Nolan's 2006 psychological thriller, The Prestige, based on the 1995 novel of the same name by Christopher Priest, revolves around rival stage magicians in Victorian London. They feud over a perfect teleportation trick in which the performer appears to transport across the stage instantaneously. It is revealed that one of the illusionists has actually been using a doppelgänger to perform the trick -- his twin brother.

Another great use of doppelgängers appears in Stephen King's book, which was also made into a fantastic HBO series that was canceled way too soon: The Outsider. In it, the antagonist can use the DNA of individuals to become their near-perfect match through a science-fictional ability to transform physically. The allusion to it being a doppelgänger is made by the group trying to stop it from killing again.

Take these 17 celebrity pairs, for example: in Hollywood alone, there are plenty of celebrity lookalikes. You wouldn't believe they don't share the same genes. See what the stars have in common besides their physical traits as well as how they handle the comparisons below: