"I'm the luckiest grandpa ever.. I get to see Jackson almost every single day.. often several times each day... thank you, Zach and Tori, for coming to the farm so often," he captioned the adorable image.
Tori and Zach welcomed their first child together, Jackson, on May 12 of this year. He was born with achondroplasia, the same form of dwarfism as Zach.
“Baby Jackson came in as [a little person] — just like me,” he previously explained. “Yeah, we’re super excited for it, though. We’ll hope to just give him a healthy, happy life and support him in every way. He can experience as much as the world as Tori and I have been able to and hopefully much more.”
Scroll through the gallery to see more photos of baby Jackson!