Thessaly is a witch from Ancient Thessaly. Thessaly is the last of Dream's lovers; at some point in the past, Thessaly was involved in a relationship with Dream.
A remorseless character, Thessaly is driven solely by her own self-preservation and has no problem killing, though she isn't malicious, harming only those who would attempt to harm her.
In A Game of You, she was living in an apartment building with Barbie, Wanda, Foxglove, Hazel, and a man named George. Thessaly kept to herself in the building until she was nearly killed by the Cuckoo who lived in Barbie's dreams, that was acting through George. Thessaly murdered and decapitated George, then bit out his tongue and put nails through his eyes to keep them open, using her magic to make him talk. Thessaly found out the Cuckoo was behind the attack and along with Hazel McNamara McNamara and Foxglove using her magic she got the moon to allow her to journey into the Dreaming to kill the Cuckoo.
She meets the Cuckoo, but it uses mind control on her rendering her defenseless. With Thessaly rendered inactive, the Cuckoo carries out its plan and destroys the dream land of its birth. With The Land destroyed, Thessaly, Hazel, Foxglove, and Barbie were trapped. Barbie was granted a boon by Dream. Thessaly wanted Barbie to wish for the Cuckoo to be killed but Barbie refused and asked for all four women to be returned to the waking world safe.
Thessaly using the moon to transport herself to the dreaming had dire consequences on the real world and caused a storm. Thessaly's apartment building was destroyed and Wanda another resident of the building was killed. Thessaly was not intimidated by Dream when they met in a skerry and chastised his actions. Months later she, to her surprise, dreamed of the Dream Lord, which he had not expected or desired, yet the two had a long conversation that eventually led Dream to offer Thessaly a stay in the Dreaming. Dream quickly became hopelessly in love with Thessaly, though she did not truly feel likewise, and realized it when he stopped courting her and resumed working. Thessaly left Dream, who did not attempt to convince her to stay. Dream was crushed by the break-up, and vainly hoped he would see Thessaly when he accompanied Delirium on her quest to see Destruction.
In The Wake, Thessaly displays genuine grief at Morpheus' death and cries. Thessaly and Dream met once later when Dream was threatened by the furies who entered the Dreaming through Lyta Hall. Thessaly made a circle to protect Lyta making it impossible for Dream to kill the living body of Lyta in the waking world without breaking some sacred laws and serious consequences. Dream and Thessaly mused that she may have done so out of spite. Dream said that he never intended to hurt her, but she spitefully replied that he had regardless of intentions. Thessaly would to her surprise miss Dream's company and later said to Lyta that she wanted to kill her for killing Dream.
Thessaly has continued to have adventures of her own in two limited series. In the first series, she battled and murdered several death gods and in the second series, she is forced into becoming a "Witch for Hire" and becomes a monster contract killer.
- Ancient Thessaly (Aeolia) in real life was a famous location in Greek mythology. It was a part of Greece that still has Mount Olympus, Ancient Pthia (the kingdom of King Achilles), and the Plain of Aeolus (4.999.353 acres of flat land) in it. Lastly, Ancient Thessaly it was the site of the Titanomachy.