Victor Aguilar, 32, said he attended the game against the Detroit Tigers with his cousin and uncle. Aguilar's cousin, who was visiting from Texas, wanted to take a picture with the mascot, he said, so the group approached the Moose.
"He was walking towards me. I was walking towards him," said Aguilar, who never expected what came next.
"I was going to go like this (showing an embracing arm) to take a picture with him (the Mariner Moose) when he pushed me out of the way, and hit my arm and neck, and hit my stomach," he said.
The Moose then walked off, Aguilar said, leaving him and those around him completely baffled.
"I was like, 'What's going on?'" he said. "There were more people there, and they were like, 'What's his deal? Why'd he do that to you?"'
Aguilar, who underwent disc replacement surgery just a month ago, said the pain from the blows prompted him to visit the first aid crew at Safeco Field.
"They told me, 'You want to go to the hospital?' And I said, 'No, let me just put ice on it,"' he said.
He felt better after about 15 minutes, Aguilar said, but the pain returned when he got up to leave. Aguilar still has a fresh surgery scar on his stomach several inches long.
"So they took me in a wheelchair all the way to my car," he said, adding once he got home, he felt worse.
"My wife said, 'Hey, you need to go to the hospital,'" said Aguilar, who spent a night at Evergreen Hospital. At home, he continues to ice the scar, and wear an elastic band around his torso for support.
Aguilar contacted the Mariners association, who told him the incident is under investigation.
"He (the spokesman) said, 'Because you left the game in the eighth inning, I want to invite you to come over, to see the Mariners again.' And I said, 'No, I don't want to come back. I don't want to come back. You know, I'm really disappointed with you guys,"' said Aguilar.
Aguilar said he's only got a few simple requests for the Mariners.
"I don't want to get any money out of this," he said. "I just want them to pay my bill, discipline the Moose, and do a little more investigation. Maybe he was drunk, on drugs, who knows the way he was acting."
The once-avid fan said he was especially disappointed by the Moose, who has helped him and his family make fond memories in the past. On his refrigerator is a photo of Aguilar's son and the Moose posing for the camera at a game earlier this month.
But Aguilar and his family's days of cheering for the Mariners may be over for good.
"I don't want to go back," he said.
Mariners spokesperson Rebecca Hale said officials will question the mascot's security members who were present at the time of the alleged beating. However, she added the Moose has "no recollection of him bumping anyone, let alone shoving anyone." Hale said the mascot's large headpiece sometimes limits his vision and causes him to bump into things with his antlers. The team's investigation is ongoing.