Alien Archetypes

Poul Anderson's Merseians, like Dan Dare's Treens, are bald, green, humanoid conquerors whereas William Dexter's Vulcanids, like HG Wells' Martians and Doctor Who's Daleks, are evil, non-humanoid monsters. These five archetypes are not equally known to the public. In fact, the public thinks that "Vulcans" are not giant adaptable anemones but pointed-eared logicians inter-fertile with Terrestrials and Star Trek adds the humanoid Klingons to the list of aliens-as-threats.

In some sf, e.g., Quatermass, all aliens are threats whereas Anderson presents every kind of alien from Merseians and Chereionites to Cynthians and Wodenites - those are just four of many in one series - and CS Lewis deliberated reversed the archetype, presenting aliens as threatened.

(Couldn't sleep so got up to write this short post.)