Pre-school brand to headline at the Queen Elizabeth Olympic Park in Stratford.
New location will hold 45,000 visitors, up from last year's 30,000.
Coolabi teams up with Fun Kids Radio and LolliBop Festival to promote pre-school brand.
ZingZillas, Mister Maker, The Gruffalo, Moshi Monsters, Skylanders, Dick & Dom and more head to kids’ festival.
Mister Maker and Waybuloo characters to appear at kids' festival this summer.