A baby kangaroo is called a "joey." This term is commonly used to refer to the young of various marsupials, but it is particularly associated with kangaroos, which are one of the most recognizable marsupial species. After birth, the joey is extremely underdeveloped and crawls into its mother's pouch, where it continues to grow and develop for several months. Inside the pouch, the joey receives protection and nourishment from the mother’s milk. This unique reproductive strategy exemplifies the adaptability of marsupials to their environments and their evolutionary success in diverse habitats.