Maine Coons are known for being on the larger side (the heaviest cat in the world, Samson, is one) but Omar is really something else.
And once you've been on Cats of Instagram, it appears the sky is the limit. The current record-holder, from the United Kingdom, is also a Maine Coon which is just over 118cm long.
ME coon Ludo, who lives in Wakefield, might be ousted after Melbourne-based Omar, who is the same breed, was revealed to be 2.33cm longer.
Ms Hirst, who lives in Melbourne, said that Omar's favourite dinner was raw kangaroo and his favourite activity was doing nothing...
The Maine coon cat has received a lot of attention since Hirst started an Instagram account for Omar, which now has almost 21,000 followers.More news: Trump will not announce promised embassy move during Israel trip
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"All of our friends want to come over and see our cat", Ms Hirst said.
Guinness representatives in London confirmed they had received an application "from Omar and his family" but Ms Hirst said staking a claim to fame is "not important" to her.
But she has to lock him out of their bedroom at night.
Despite skyrocketing to global fame, Omar is a reluctant celebrity.
"He's just looking forward to napping on the trampoline, chowing down on some more kangaroo and trying to keep us awake at night", she said.