"My grandfather."
He says his grandpa has been supporting him his whole life.
"He was recording me when I was a little boy in Pop Warner," Mostert said.
RELATED: Who is Raheem Mostert? Here's what to know about 49ers running back who stunned America in NFC Championship
Mostert is coming off the biggest game in his career, the NFC Championship against the Packers where he rushed for 220 yards and four touchdowns.
Yet, he still looks back at those childhood game tapes, every time he visits grandpa.
"We still have the VCR's," he said. "I know he's so proud."
Now, his grandpa will get to watch him on play on the world's biggest stage.
"He's coming to the game!" Mostert said, beaming. "I gave him the invite and he almost burst out in tears he was so excited."
They still have all the old VHS tapes, but this time, he says Gramps will record with some newer technology.
RELATED: Former surfer Raheem Mostert says new Niners contract forbids catching waves
In Miami, we learned there are many layers to Raheem Mostert.
He loves to surf, has a bible verse, tattoo, and talks at length about not just having goals, but having "whys."
Watch the video posted above to learn more about the 49ers rising star.
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