The good folk at Game Informer have revealed the first deatiled look at Mass Effect: Andromeda's alien bad guys, a new race known as the Kett. Art director Joel MacMillan says in the video that BioWare took a different approach to the creation of this race than it did with the ETs of previous games, in order to adequately differentiate them from the Milky Way aliens we're more familiar (and comfortable) with.
Unlike the "clean, sleek, hard surfaces" seen on the bulk of the races in the Mass Effect trilogy, the Kett have a more "organic" look to their armor and architecture. BioWare went back and forth a bit on just how alien to make them, though. There was some thought given to designing them to be dramatically more alien than the Asari or Turian, but ultimately the decision was made to keep them bidpedal—and clothed, too. ("Definitely the right choice," MacMillan said.)
Even though the Kett will be the antagonists in Mass Effect: Andromeda, it sounds like they aren't all bad: MacMillan said BioWare wants them to be "foreboding, but never to the point of being ugly. You still want to be able to empathize with these guys." Sounds a lot like "Kett crewmember confirmed" to me.
Mass Effect: Andromeda is currently expected to show up in March 2017. Have you seen the N7 Day trailer? We've already mined it for clues right here.