Jan. 8 (UPI) -- Minor League Baseball fans are mourning the loss of Home Run Derby, the bat dog.
The infamous bat-carrying golden retriever died Saturday. The Trenton Thunder announced that the team will celebrate Derby Day on Jan. 26 on what would have been his 10th birthday.
"It is with great sadness that we share the news that our wonderful second generation Bat Dog, Home Run Derby, passed away this weekend," the Thunder said in a statement.
The Thunder is asking fans to make monetary donations in Derby's name to Trenton Thunder charities or to Delaware Valley Golden Retriever Rescue.
Derby's father, Chase, was the team's bat dog before he took over the role. The bat dog works at every home game.
"Derby was one of the biggest parts of our identity in the nine years of his life and it breaks my heart to share this news with our fans ahead of our 25th season," Thunder General Manager and Chief Operating Officer Jeff Hurley told MiLB.com.
"His presence at our games and in the community was massive and every person and dog that interacted with him will miss him dearly."
Derby was born Jan. 26, 2008. He had three brothers and two sisters. Derby's brother Ollie served as the bat dog for the New Hampshire Fisher Cats before he retired in 2016.
Derby made his debut with his dad in 2008. He retrieved his first bat in 2010. He also brought bottled water to umpires and made special appearances. His pregame routine included bringing a baseball to the pitcher and catcher.
The beloved bat dog also was featured on a bobblehead and the subject of a book. He became a father to a son and daughter in 2013.