One who acts like he/she has more authority than has been bestowed to him/her. Often characterized as being loudmouthed, obnoxious, and having no friends. A compound of douchebag and hippopotamus.
A human who is such a giant douche bag that they may also bear Hippopotamus DNA. Someone who is so big of a Douche that it's impossible to overlook their presence.
Hey.. its Christmasand that guy took up 3 parking spaces....what a Doucheoppotamus.
Don't look now but I think there's a Doucheopottamus coming over to buy you a drink.