This problem is solved by ART:

|[![enter image description here][1]][1]|[![enter image description here][2]][2]<br/><br/>[![enter image description here][3]][3]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;|
|--|--|

The depiction to the left is that of a sphinx (Gustave Moreau's *Oedipus and the Sphinx*), those to the right are symbolic representations of nightmares (Daumier's *Horse Meat is Healthy and Digestible* & Füssli's *The Nightmare*, resp.) (I thought I remembered seeing a combination of the two, but I might be mistaken).

**The sphinx suffocates by burdening her victims.** This can be done both physically and psychologically. 

This is not at all surprising, given the [etymology][4] of the word '*sphinx*':

> "*In English from early 15c., from Latin Sphinx, from Greek Sphinx, **said to mean literally "the strangler,"** a back-formation from sphingein "to squeeze, bind" ([ref.] 'sphincter')*"


  [1]: https://i.sstatic.net/KoWfF.jpg
  [2]: https://i.sstatic.net/lieqZ.jpg
  [3]: https://i.sstatic.net/T0r6g.jpg
  [4]: https://www.etymonline.com/word/sphinx