A person who is in a position of authority, the bringer of woe and disarray yet of a simple nature; hereby making them a doom muppet.
______ told me to do ______ but, ______ is already doing it. Man ______ is a right doom muppet!
A person who never brings any joy.
Someone who can never see the good side of anything - while at the same time contributing nothing of use or having any talent.
The studio manager should lighten up - she's a right doom muppet.