What do you call this in the picture?

Curmudgeon, The reason why it is called sleep paralysis is because He/She thinks that a monster is really trapping him/her, preventing that person from sleeping to get out of bed. Therefore, he/she is "paralysed", meaning that the sleeper (person sleeping on the bed) cannot move or anything because the sleeper is scared about what happens to himself/herself if he or she does anything wrong which angers the monster

very interesting. thx for sharing!