Hero the Hedgehog and Whizbee the Bee have been revealed as the official mascots for this summer's IAAF World Championships and World Para Athletics Championships respectively.
The pair were selected from over 4,000 entries to a competition run by the two events' organisers and BBC children's programme Blue Peter.
The winning designer is nine-year-old Elinor from the West Midlands.
"It is so exciting that my designs were chosen," she said.
"I chose Whizbee and Hero because they are endangered species and are survivors. Bees are really important because they make the world go around and hedgehogs are determined and brave.
"It's really cool getting them made into proper mascots. I can't wait to see them in the summer."
Olympic heptathlon champion Dame Jessica Ennis-Hill, who was part of a judging panel including representatives from the Organising Committee, the International Paralympic Committee, the IAAF and Blue Peter, said: "I think Elinor's reason for choosing a bee and hedgehog, and the fact that they are creatures in our everyday lives in Britain, made the designs stand out.
"There were so many good, creative designs it was pretty hard to choose a winner.
"Hopefully the mascots will bring a lot of fun and energy to the Championships."
This summers Championships will be the biggest events to be staged at the London Stadium since the 2012 Olympic and Paralympic Games.
It is the first time both Championships have been held in the same city, with over 3,000 athletes from over 200 nations competing over 20 days of action.
The World Para Athletics Championships run from 14-23 July, with the IAAF World Championships following from 4-13 August.