Erato

Erato was a Tythonian ambassador. He was sent to Chloris to negotiate a trade deal, but instead found himself trapped by Lady Adrasta, who captured him to prevent any infringement on her trade monopoly.

Biography
Erato was sent to the planet Chloris in a Tythonian ship to try and obtain trading rights between it and his home planet of Tythonus. However, before he could make any contact with the inhabitants, he was captured by Lady Adrasta, who stole his communication device and threw him into "the Pit" to maintain her monopoly on the metal in Chloris.

Adrasta threw people into the pit, where they were supposed to be eaten by Erato. However, as he did not eat people, they either died of fright or were crushed under Erato's weight.

Erato managed to transmit a distress signal which was intercepted by the Fourth Doctor and Romana. The Doctor managed to meet up with Erato. As they were unable to communicate, Erato drew a picture of his communicator and the Doctor agreed to fetch it. Erato moved out of the cavern to meet a party led by Adrasta. Under the hypnosis of his communicator, Torvin and Edu returned it to him.

The Doctor touched it, allowing Erato to use his larynx to talk. Adrasta was forced into using it and Erato related his story. Realising her betrayal, Adrasta's people turned on her. Erato and the Huntsman's Wolfweeds killed her. Erato then ate the Wolfweeds, consuming them for their chlorophyll. The Doctor discovered that the Tythonians had declared war on Chloris due to the missing ambassador, and had dispatched a neutron star to collide with Chloris's star and destroy the system. It was due to collide within twenty-four hours. The Doctor used his TARDIS to stabilise the star with a tractor beam, while Erato wove a metal covering around it, neutralising the danger.

The Doctor's last act on Chloris was to push Organon, now one of the de facto rulers, toward a mutually beneficial trade agreement with Erato and the Tythonians. Chlorophyll was taken by Tythonus in exchange for metals. (DW: The Creature from the Pit)

Behind the scenes

 * Erato was the name of the Greek muse of lyrical poetry.
 * The 2|entertain documentary, Team Erato, looked at the hardships faced in bringing the creature to life.