Saint West and his cousin Reign Disick had a joint 'Monster Mash' party on Sunday (03.12.17).
Kim Kardashian West and Kanye West's son turns two on Tuesday (05.12.17) and Reign, the son of Kim's sister Kourtney Kardashian and her ex-partner Scott Disick - with whom she also has seven-year-old Mason and five-year-old Penelope - both got matching 'Monsters Inc.' cakes inspired by the movie's prequel made for them.
Saint - who has four-year-old sister North - had the Disney movie's character Mike Wazowski iced on his cake, whilst Reign had giant fluffy monster James P. Sullivan.
'Keeping Up With the Kardashians' star Kim took to Snapchat over the weekend to share snapshots of the cousins' festive day, which included going ice skating and meeting Santa.
It comes after the 37-year-old beauty threw a cherry blossom-themed baby shower last month, for the upcoming arrival of her third child via surrogate.
The family enjoyed a Tea for Three party staged in a "cherry blossom forest" at their Los Angeles home.
Guests at the bash included Kim's half siblings Kylie and Kendall Jenner, sister Khloe Kardashian, and pals Chrissy Tiegen, hairstylist Jen Atkin, and eyebrow artist Anastasia Soare.
North was also in attendance, teaming a Chinese-style dress with a pair of fuzzy slippers.
Kim shared a Snapchat clip of the youngster and wrote: "Look at the cute little dress Northie is wearing."
Kim and her guests all shared videos of the bash on their social media accounts, with Kylie - who is reportedly expecting her first child with Travis Scott - heard to exclaim the decor was "so gorgeous" as she made her entrance.
Kim gave her guests party favours from her latest KKW Beauty label range, the upcoming new fragrances Crystal Gardenia, Crystal Gardenia Citrus and Crystal Gardenia Oud.