He has written scripts for over 70 animated films, and "is considered one of the most important living Russian authors of children’s books.

After three years in the Soviet North Sea Navy, he studied in Moscow at the Maxim Gorky Literature Institute.

He is the author of many works for children, such as “A Tale with Details”, “Papamamalogy”, “Parenting Adults”, “Grandma Boa”, “Bad Advice”, “Fortunetelling on Hands, Legs, Ears, Back and Neck”.

In the late 1990s, Mikhail Epstein and Alexander Genis included Grigory Oster in the list of “Who is who in Russian postmodernism”.

According to the observations of critics, his aesthetics are distinguished by "stylistic eclecticism, subtext, citation, play of signs, irony, parody and stylization."