Greedy grizzlies are being celebrated as Fat Bear Week announces this year's most impressive beasts preparing to enter hibernation. 

The much-loved contest pits the brown bears of Alaska's Katmai National Park & Preserve against each other to well they bulk up for winter hibernation.

The US National Park Service (NPS) launched this season's competition on September 5 by highlighting some previous year's winners.

The winner of Fat Bear Week 2024 was Grazer, a mother bear who successfully defended her title for the second consecutive year.

She received over 71,000 votes, more than double the votes of her closest rival, a male bear named Chunk.

NPS said: 'Big, bold, and bear-y round: a fat bear champ will soon be crowned!

'This is how legends are made. Fat Bear Week, the ultimate bracket competition where the public votes for the bear that achieves peak spherical status, is just around the corner!

They confirmed the event will take place from September 23 to September 30, with a 'chubby cubby appetizer', Fat Bear Junior, kicking off on September 18 to September 19.

NPS added: 'From tubby titans to gargantuan gluttons, get ready to cheer for the heftiest bears in Katmai National Park & Preserve's Brooks River!'

Fat Bear Week has been running since 2014, making 2025 its 11th year of celebrating the fattening efforts of brown bears in Katmai National Park.

NPS said this year's bear bios would be revealed soon.

In 2018, Bear 409 Beadnose won the contest, followed by Bear 435 Holly in 2019.

The following year, Bear 747 won and would go on to win again in 2022 after its crown was stolen by Bear 480 Otis in 2021.

In 2023 and 2024, Bear 128 Grazer claimed the winning title and it is yet to be seen which bear is announced winner in this year's competition.

It comes after a fight between two Fat Bear Week contestants halted the competition after one bear killed another in a gruesome, televised brawl, last year.

An adult male and female were caught on the competitions' livestream fighting in the mouth of the Brooks River in Katmai National Park, Alaska.

Resident naturalist for explore.org, Mike Fitz, gave commentary on the deadly altercation between the two bears.

Fitz said: 'Watching bears attack other bears is often difficult to see, especially if a bear kills another bear so this is a difficult situation to witness.'

The commentators had little idea what started the fight, but said they didn't believe it was over food resources but rather a 'dominance' fight.

Katmai Park Ranger Sarah Bruce said: 'He's a predator toward this female bear... We don't know why they're fighting... [These are] two bears very clearly not playing around.'

The two bears were seen on the livestream footage fighting in the river. Adult male number 469 and adult female number 402 battled for more than 20 minutes, before 402 was killed by 469.