The This Morning presenter took to her Instagram page on Monday to post a never-before-seen picture from her eldest son Harry's first birthday, where she was seen posing with the cuddly green giant.
In the caption, the doting mum claimed the famous mascot was a "hero" in their household. "So very very sad to hear the news that @officialgunnersaurus has been released by @arsenal," she wrote.
"He was at my son Harry's first birthday and he's a hero in our house! He'll never be extinct in our eyes. Bring back Gunnersaurus! #dinohero #legend."
WATCH: Holly Willoughby reveals difficult family decision
Holly, 39, shares children Harry, now 11, Belle, nine, and Chester, six, with TV producer Dan Baldwin.
The family's disappointment comes shortly after Holly revealed a football rivalry in her house, with her husband an ardent Arsenal fan, while their youngest son supports rival team Chelsea.
For Chester's sixth birthday last week, he was treated to a Chelsea football club-themed birthday cake. In her caption, Holly admitted Dan was less than impressed with the creation, and blamed friend and Chelsea manager, Frank Lampard, for Chester's choice of club.
The This Morning presenter posted this throwback photo
"If anyone knows my @arsenal loving husband you'll know how much this cake for Chester's birthday is killing him," she said. "I blame you entirely @franklampard.
"However that's our boy all over... marching to the beat of his own drum, spreading absolute joy wherever he goes ... we love you so very much Chester Chops... how is my beautiful baby six already!"
Frank was among those to reply to the post, joking: "Happy Birthday Chester my little Chelsea friend! The boy just has amazing taste in his football teams. Next stop a Chelsea cake for Dan on his birthday and my work is done. Hope he has a great day. X."
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