The blind god tricked by Loki into killing Baldr was Höðr. In the best-known version of the myth, Loki exploited Baldr’s one vulnerability and guided Höðr’s attack.
Baldr’s mother, Frigg, had obtained oaths from nearly every thing in existence that it would not harm her son. She overlooked mistletoe, considering it too insignificant or too young to pose a danger. The gods then amused themselves by throwing weapons and objects at Baldr, all of which failed to injure him.
Loki made a weapon from mistletoe and gave it to Höðr, who could not see. In Snorri’s Prose Edda, Loki helped direct the shot, and the mistletoe killed Baldr. Odin later fathered Váli, who rapidly grew to avenge Baldr by killing Höðr.
The story varies across sources. In Saxo Grammaticus’s Gesta Danorum, Hotherus is portrayed as a mortal hero who kills Balderus, rather than simply a blind divine instrument. Despite those differences, Höðr is the standard answer to this quiz question.