Rapido is a jet set-wannabe with a huge ego to maintain. To get over his large self-doubts and low self-esteem, he acts in a condescending manner and often boasts having personal connections to various celebrities. Rapido is also a hypocrite, scolding Razmo sharply for engaging in an activity, then secretly pursuing the same later on. Rapido only has interest in himself and will not aide Razmo at all, unless the situation adversely affects himself. His interests include ratboard racing, celebrity magazines, fashion, house music and feeling important and wooing women.
Razmo is the shorter and stouter rat. He is a highly productive genius and mechanic, having invented the ratboard and being responsible for all mechanical and electrical issues. He is also forced to perform all chores as Rapido never lends a hand. This has led Razmo to become depressed, emotionally scarred and obsessive-compulsive. Razmo is also childish, sometimes speaking to a plush toy and wetting the bed. His interests include playing stringed bass, jazz, counting the cheese, inventing and making friends. In the original Rapido short, Razmo had a Deep South accent; the voice was changed to have a slight Brooklyn accent during production of Ratz. Oddly, Razmo is called 'Ratz' (as in the name of the show) on the blurb for the show in Sky programme guides.