Gachatara was a mikyuum that became one of Aruruu's pets. He is shown in the opening of every Utawarerumono main episode. His horn is white and he has bright gold eyes. Most of his fur is white, but the tips of his tails, ears, and a patch on his back over his shoulders are dark blue.
Chikinaro brings Gachatara into the castle and properly introduces him. Hakuowlo initially refuses to buy it, stating that they already had one big eater (Mukkuru) and that it was not a nessecity. When Oboro learned that its liver could cure any illness, he declared he would buy it and use it to cure Yuzuha.
He made the mistake of looking at Gachatara with "blood in his eyes" and sensing danger, Gachatara released a sonic blast in defense and escaped. With both Chikinaro and Oboro in pursuit, Gachatara ran to where Aruruu, Yuzuha, and Mukkuru were resting. When Oboro arrived in pursuit, he asked Aruruu, who had the mikyuum, to give it to him in exchange for a bunch of honeycombs. As he was only bluffing and had no honeycombs, Aruruu cheerfully said no.
Gachatara "speaks" to Aruruu and she names him Gachatara as she says the mikyuum will be killed if Oboro gets him. Yuzuha declares that she doesn't want to be cured if it meant killing Gachatara, forcing Oboro to relent. Hakuowlo then agrees to buy Gachatara for an apparently large sum of money from Chikinaro.