The Tsufuru-jin race, also know as the Tuffles, Tsuffles or the Tsufuru depending on the version of dub you experience, were the people who lived alongside the Saiyan people on the Planet Plant. The Saiyans may have been strong, but the Tsufuru were very smart in terms of their technology. In fact, they were responsible for such creations as the scouters and cannon blasters, which the Saiyans eventually stole once they wiped out the Tsufuru during a night when the full moon shone down on Planet Plant and they all transformed into Oozaru.
The evil villian Baby from Dragonball GT was a machine mutant created from DNA of the Tsufuru King, and thus has a urge to get revenge on the Saiyans. The Tsufuru people are also referenced and play a part in the Dragonbal Z OVA; Plan to Eradicate the Saiyans.