Crow serves as an avian companion and assistant to Professor Gulliver. This character travels alongside Gulliver, a human boy, and other companions on their interstellar voyage to the Planet of Blue Hope aboard the spaceship Gulliver. Crow actively participates in the group's adventures and confrontations with adversaries encountered on alien worlds.

In the English-language adaptation of the film, the character receives the name Sylvester. This naming represents a deliberate alteration from the original Japanese version, where the crow remained unnamed and was referred to simply by the species identifier "Crow".

The character's origins, personal history, and any significant development during the narrative remain unexplored. Crow's involvement is consistently portrayed as a supporting presence within the primary ensemble throughout the journey.

No official sequels, prequels, spin-off media, or adaptations across other formats explore Crow's background or expand upon the character's role beyond the events depicted in the original animated feature film. The character does not appear or receive development in any other officially recognized stories or continuations.