From the announcement:
WizKids, the industry leader in quality pre-painted miniatures, is pleased to announce their newest line of RPG miniatures, Thistleguard™, created with younger RPG players and their families in mind. Featuring a variety of child age human figures spanning a wide range of classes, the Thistleguard miniature collection is set to launch early 2018.
The Thistleguard realm takes on a new twist to an otherwise classic fantasy world where kids are the adventurers. These fledgling adventurers gain their powers and abilities at a young age, allowing them to defeat the evil creatures in their world. Their powers, however, are fleeting. As the children grow, they begin to lose their powers over time. When they enter adulthood, most forget they ever adventured in the first place as everyday responsibilities take hold.