Look at that adorable costume!

On Saturday, Nov. 14, Fergie took to Instagram to share a precious photo of her two-year-old son, Axl, in honor of her husband Josh Duhamel's 43rd birthday!

"Let's fire it up for your birthday daddy!!! ???," the 40-year-old singer captioned the sweet snapshot of her little guy.

Josh and Fergie tied the knot in 2009 and welcomed Axl, their only child, in August 2013.

Click through the gallery below to see more of Hollywood’s cutest kids!