Rocky Thirteen Barker, meet Rocky Balboa. 

On the occasion of Kourtney Kardashian and Travis Barker's son's first birthday, baby Rocky was given a very unique present from the one and only Sylvester Stallone—the writer and star of the 1976 classic Rocky: a handwritten note made out especially to him.

"One of the most special Birthday gifts," Travis wrote on Instagram Stories Nov. 4 alongside a snapshot of the one-of-a-kind letter, which was written on Sylvester Stallone's stationary. And according to the Blink-182 drummer, Kris Jenner was behind the over-the-top gift, as he added, "thank you @krisjenner @officialslystallone."

As for the card itself, it read, "Dear Rocky, My name is Rocky too. Your name is very special and is identified with wonderful things."

The Oscar nominee noted that while "life has many challenges you will face," he encouraged the 12-month-old to "show dedication and determination!"

"You must never give up on your dreams, never!" Sylvester added. "Now most importantly, you must always value family, friendship and loyalty over fame and fortune!"

He ended the message with, "Keep punching, Sly 'Rocky Stallone," a nod to his character Rocky's career as a boxer in the Oscar-winning film.

The birthday card was especially meaningful for Travis, who had previously revealed that the film was one of the inspirations behind his son's name, telling Complex in July of last year that he considers it "the greatest boxing movie of all time."

The 48-year-old explained the name was also a tribute to Suicidal Tendencies guitarist RockyGeorge. And as for middle name Thirteen? Travis joked, "13 is just the greatest number of all time."

Fittingly, Rocky was the 13th grandchild born into Kris' family, which she noted in her birthday tribute to her grandson.

"I can't believe you are already a year old!" she wrote on Instagram Nov. 1, alongside several photos of Rocky. "It feels like just yesterday that we were welcoming you to the world. You are grandchild number 13 and the most precious little smiley boy I have ever met!!"

She added, "I can't wait to watch you grow up and I am so thankful to God that He chose me to be your grandma. I love you so so much and I can't wait to watch you grow."

But Rocky is hardly the only one in his family with a unique moniker, as his parent's blended family includes Mason Disick, 14, Penelope Disick, 12, and Reign Disick, 9—who Kourtney shares with ex Scott Disick—as well as Travis' children Landon Barker, 21, Alabama Barker, 18, and stepdaughter Atiana De La Hoya, 25, who he coparents with ex-wife Shanna Moakler.

For a look back at Rocky's first year, keep reading.

Kourtney Kardashian and Travis Barker's son Rocky Thirteen Barker played with some unique toys, embracing a globe bouncy ball and a skeleton prop ahead of Halloween.

For Rocky's first Halloween, Kourtney and Travis dressed him in a sweet bat onesie.

At 11 months, Rocky also sported a skeleton outfit for Halloween 2024.

The couple took Rocky to the ocean in an October 2024 snap.

He took in the views in September 2024. 

The reality star bundled up in a cheetah print coat as she carried Rocky in this snapshot shared by Travis in September 2024.

The Blink-182 drummer kissed his baby boy on the cheek in this September 2024 picture.

Say cheese! Kourtney snapped a breastfeeding selfie with Rocky in September 2024.

In August 2024, Kourtney shared photos from the road as the family joined Travis on Blink-182's summer tour, including this snapshot of herself nursing Rocky backstage.

Rocky had a blast riding on an UFO buggy backstage at a Blink-182 show.

"Happy Father’s Day @travisbarker !!" Kourtney wrote to Travis on Instagram on Father's Day 2024, sharing never-before-seen pics of her husband with their son. "Beyond grateful for the Dad that you are to our baby boy, and all of our kids."

Kourtney continued, " You keep us safe and protected and take care of us. Having a family with you is heaven. Happy to celebrate you!"

Kourtney also included this pic of Travis and Rocky in her Father's Day tribute.

Travis' daughter Alabama shared this photo of the couple with baby Rocky in June 2024.

Travis played with his baby boy on a private plane.

The Poosh founder and the rocker shared a sweet kiss while holding their son Rocky, who they welcomed on Nov. 1, 2023.

Travis commemorated Kourtney's first Mother's Day with Rocky, writing on Instagram in May 2024, "Happy Mother’s Day to my best friend and partner."

"Our children are so lucky to have you," the musician—who is also dad to step-daughter Atiana de la Hoya, son Landon Barker and daughter Alabama Barker with ex Shanna Moakler—continued in his tribute to Kourtney. "Thank you for filling our home with love, laughter, and joy."

Sharing photos of Kourtney and Rocky, Travis added in his Mother's Day message, "I love you forever and ever my wife @kourtneykardash."

Rocky fell asleep during this tender moment with Kourtney, who also shares kids Mason, Penelope and Reign with ex Scott Disick.

Travis shared a sweet look at life with their baby boy, captioning this mother-son photo on Instagram in April 2024, "I love our life together. Thank you for being the most amazing wife a person could ask for."

The Kardashians star celebrated her 45th birthday alongside Travis and Rocky in April 2024, with the family ringing in the milestone with a firework display.

Rocky took his first international flight when the family flew down to Australia for Travis' Blink-182 tour in March 2024.

Travis splashed around the gentle waves with his son during a family vacation in the Bahamas.

Kourtney and Rocky shared a bed in this sweet snap posted by Travis on Mother's Day 2024.

The drummer's baby boy joined him behind the kit.

Kourtney and baby Rocky kicked back by the pool during a tropical vacation in April 2024.

Travis shared this adorable photo of Rocky and his mama on Kourtney's 45th birthday in April 2024.

The Blink-182 rocker held his son during Kourtney's 45th birthday celebrations.

Rocky donned on a pair of elf boots during Christmas 2023.