Tyra Banks Shares Wild Santa Claus Conspiracy Theory at Australian Pub Gig

Tyra Banks baffled fans and aroused some concerns during an on-stage appearance Sunday in Sydney, Australia ... ranting about Santa Claus trying to sabotage her brand.

The supermodel, TV host, and businesswoman reportedly DJ'd a set at a local pub when she launched into a tirade accusing Kris Kringle of counterfeiting her SMiZE & DREAM ice cream.

Donning a knee-length yellow Santa hat, long canary-yellow wig, and skintight black dress, Tyra went off ... claiming Santa is lying about his intentions with the snacks we traditionally leave out for him.

In a video shared on socials, she insisted, "Child, he ain't biting that cookie. He ain't sipping that cream. He taking a bowl from your cabinet ... and he putting a little bit of cookie, and he putting a little bit of that milk, and he mixing it up. And then he put it in your freezer. And he trying to make it taste like Santa SMiZE, and it tastes like Santa sh*t!"

The video features several more inexplicable moments spliced together.

"I think I'm going crazy!" she says in one isolated clip ... the context of which is not clear.

Back in October, she admitted to Australia's News.com.au that people thought she was "crazy" for her SMiZE & DREAM store in Sydney selling "hot ice cream."

She told the outlet ... "They drop in the DMs and ask if I need help. I know my desserts. It's a drinkable ice cream, but it's not a shake. We didn't just take it and melt it."