Yes, some fictitious alien races have extra and/or less body parts (I.e. eyes, ears, noses, nostrils, mouths, heads, arms, legs, faces, fingers/toes, hearts, livers, lungs, kidneys, stomachs, forearms, forelegs, horns, wings, tails, etc.).
Yes, some fictitious alien races look like mythical creatures (i.e. satyr, centaur, merfolk, harpy, dragon, cerberus, elf, vampire, etc.)
Yes. Some alien races have less body parts (i.e. headless, eyeless, noseless, mouthless, earless, etc.). But currently, it is unknown.
In my opinion, yes. Some alien races have supernumerary body parts (i.e. multiple heads, arms, legs, fingers and toes, etc.). But currently, it is unknown.
Yes, some fictitious alien races look like anthropomorphic (and also non-anthro and semi-anthro) animals (I.e. mammal, reptile, avian, amphibian, insect, arachnid, crustacean, gastropod, cephalopod, piscine, annelid, reptomammal, reptavian, mammavian, insectomammal, reptamphibian, etc.)
No matter how often you ask, the only honest answer is that nobody has found ANY alien races so far, so nobody really knows anything about them for sure.
Yes. Alien races have strange appearances.
From the data we have, we have not discovered any alien races.
If there are alien races they indeed might have multiple ears.
Yes. Some alien races have two hearts.
Two pupils in the eye would be eerie,and perhaps some alien races have them.
We have not yet met any alien races. However on television and movies, ridged heads are sometimes used for alien races such as Klingons and Cardassians.
If aliens exist, the alien races may have mammavian characteristics.