Hope is not the only new specimen in Hintze Hall.
The doting mum-of-two attended a ceremony at the museum she is a patron of, where the new giant blue whale skeleton has been unveiled.
Blue whales were hunted to the brink of extinction by humans, but were also the first species we chose to save too.
"This is a landmark moment for the Museum and for the millions of people from all over the world who visit us".
Duchess of Cambridge shines in gorgeous '50s flare dress
Despite a petition to stop the move, the museum went pushed forward, saying the whale named "Hope" was "a symbol of humanity's power to shape a sustainable future".
Dressed in a pale blue A-line dress with short sleeves, Middleton opted for no jewelry for the occasion, but paired her looked with black Prada strappy heels.
On Thursday, the museum presented an official unveiling of Hope along with the time-lapse video that shows the skeleton being pieced together from start to finish. "It is impossible not to be struck by the sheer scale and majesty of this handsome creature as she dives towards you when you enter the Museum".
Hintze Hall will reopen to the public on Friday following six months of refurbishment. It is largest known animal on Earth and is suspended from the ceiling.
Fans of Dippy need not despair as the replica will in any case be preserved for posterity in a bronze cast to be placed outside the museum.
The director of the museum, Sir Michael Dixon, stressed the importance of its new collections and looking to the future.