It's the plural form of "cría", which is a noun that refers to the young of an animal.
Here are some examples:
* Las crias de león son muy lindas. (The lion cubs are very cute.)
* Los crias de la oveja están jugando en el campo. (The lambs are playing in the field.)
* Las crias de las aves necesitan mucho cuidado. (The chicks need a lot of care.)
Note: "Crias" can also be used to refer to the young of human beings, but it's not as common as "niños" (children) or "bebés" (babies).