The Kanassan warriors seen in the TV special are shown to be extremely brave. Despite knowing from their visions that they will be destroyed, they put up a good fight with Bardock and his team. They are shown to be very honorable, a good example being the conversation between Demetrious and the unnamed commander, in which after Demetrious draws blood, the commander states that "You have done well my friend... I will meet you at the door.", implying that he has served his noble duty and now must pass on to the next world.
Kanassans appear to talk telepathically to one another, as when Demetrious is seen talking, his mouth does not move. They also appear to have been able to harness ki energy, another reason why they had put up such a hard struggle against the Frieza Force.
The Kanassan war
Main article: Kanassan war
Inhabitants of Planet Kanassa, are said to possess psychic abilities, including being able to read minds and see into the future. Thus, Frieza orders their extermination out of paranoia that they could become a threat to him, or to simply use the planet's unique energy for himself. They are wiped out by Bardock's team, as Great Apes who attacked during a full moon.
In the TV special, Bardock and his crew were assigned by Frieza to exterminate all life forms of Planet Kanassa. Afterward, a remaining survivor named Toolo catches Bardock off-guard and gives him the ability to see the future. The Kanassan believes this will give him the ability to see the destruction of Planet Vegeta, and the entire Saiyan race with it, at the hands of the tyrant Frieza. Bardock then kills Toolo after Tora weakens him.
Dragon Ball Z
During Frieza's attack on Earth in Resurrection ‘F’ chapter 2, a Kanassan who serves in the Frieza Force can be seen amongst his 1000 soldiers army (led by him & Sorbet) to be easily defeated by the Dragon Team and Jaco. This would indicate that a few Kanassans survived the takeover of their planet and some may have joined the ranks of Frieza's army.
Video Game Appearances
In Dragon Ball Z II: Gekishin Freeza, Planet Kanassa is visited in the chapter "Exit the universe": during his journey to Namek, Goku senses there is something wrong on Kanassa. He lands on Kanassa and defeats Frieza's soldiers stationed there, freeing the surviving Kanassans from Frieza's rule. A Kanassan thanks him and says he looks a lot like Bardock (Goku's father), who had conquered the planet for Frieza. The Kanassan also knows about Bardock's sons, Raditz and Goku, a result of their ability to have visions.