Pratt, Seattle Seahawks quarterback Russell Wilson and singer Ciara joined Pratt on his visit to Seattle Children's Hospital.
The hospital posted an adorable photo of Pratt giving a Groot character toy to a baby who is seen reaching for the star's face hidden behind a mask.
Pratt, Wilson and Ciara also posed with some of the older kids, as well.
Some parents shared thanks for "making (their kid's) year."
The celebrities gave the children free Amazon products, courtesy of the company.
Chekc out all of the messages on the Seattle Children's Twitter page.