Imaginative Aliens

Which of the future histories in the American sequence that we have been discussing presents the most imaginative aliens? It was clever of Niven and Pournelle to make their Moties asymmetrical. However, apart from that single important difference, a Motie's body is recognizably a humanoid form with two right arms and one right ear.

Niven's three-legged Puppeteers with their brains inside their bodies are definitely not humanoid. Nor are Poul Anderson's less well known Smokesmith the Reardonite or Rax.

One of Anderson's Didonians comprises three temporarily linked bodies. Although each of these bodies is comparable to a Terrestrial animal - rhino, goose and ape - their transient tripartite consciousnesses are entirely alien. See here.

Thus, here are five interesting alien intelligences appearing respectively in four future histories:

Pournelle's CoDominium series;
Niven's Known Space series;
Anderson's Psychotechnic History;
Anderson's Technic History.