Like the Ancient Egyptians, it seems we're all obsessed with cats nowadays (despite the fact dogs are demonstrably much cooler). It seems the Big Hero 6 production team realized this and planned to combine our modern fascination with silly cats with another modern fascination - things with rockets attached to them.
Rocket Cat was a character that was originally intended to be included in the theatrical release of Marvel's animated superhero flick. However, although everybody loved the character, they couldn't find a way to meaningfully add the jet-fueled feline into the film, and unfortunately the creation was cut. It's unclear if any actual scenes were animated with Rocket Cat, but we've now uncovered a piece of concept art by Mingjue Helen Chen which shows what he/she would have looked like.
According to io9, the Japanese marketing team for Big Hero 6 loved Rocket Cat so much they still decided to use its image in promotional materials. To be fair, the concept of a Rocket Cat is the most Japanese thing I've heard in a long time.
Big Hero 6 was...