Houyo was a female Tigrours, a giant predator from the jungle planet on which Nävis' cryoship crashed.
Houyo was caught by the young human when she was still in the care of the robot Nsob, who watched over both of them for a while. When Nsob was destroyed, Houyo dragged Nävis, who was suffering from amnesia after a particularly fierce fight, to safety and took care of her, teaching her to survive in the wilderness. They became best friends once more.[1]
When Madjestœt Heiliig came to the planet to transform it into a world suitable for the Hottards, he got into a fight with Nävis on his hovercraft. Houyo attacked him to protect her friend, and bit through several of the heating tubes in the back of the head of his environmental gear. The resulting release of pressurized hot air burned her head, killing her instantly.
Houyo's dead body plunged into the waterfall below, and ended up saving Nävis, who had also been thrown into the water by Heiliig, from certain death. The young woman only had time for a short, tearful goodbye before leaving the giant creature's remains behind.[2]
Later in life, while growing up on Sillage, Nävis kept a stuffed toy modelled after Houyo.[3]