It's not a tough riddle but whatever...?

There are these three aliens in a planet Trekia, and the planet has two cultures of aliens, the carpals and the tarsals. The carpals always lie and the tarsals always tell the truth.
A space traveler arrives on Trekia and meets a party of three aliens. She asks the aliens to which culture they belong. The first one murmurs something that is too soft to hear. The second one replied "It said it was a carpal." The third one replied to the second, "You are a liar!" From this information, figure out what culture the third alien belongs to.

First one right and explains it logically gets the 12 points!

Alien 1. Made a murmured statement.
Alien 2. Alien 1 said he was a Carpal.
Alien 3. Alien 2 is a liar.

If Alien 1 was a Tarsal, he would have said truthfully he was a Tarsal. If Alien 1 was a Carpal, he would have lied and said he was a Tarsal. So, Alien 1 statement was "I am a Tarsal".

Since Alien 1 claimed to be a Tarsal, Alien 2's statement was false. So, he is a Carpal.

Since Alien 2 told a lie, Alien 3 told the truth about Alien 2 being a liar. So, Alien 3 is a Tarsal.

Although, we still don't know what culture Alien 1 is.

it's a carpal.

Trekia --> 3 aliens; 2 cultures(carpals-lie and tarsals-truth)

The 3rd one is a liar-carpal.

its the tarsals

It's a tarsal. Second one said first was a carpal, third one said second was a liar. Tarsals tell the truth, so it's a tarsal.

a tarsal. The first alien could not call himself a liar, since he'd be telling the truth if he were a liar and lying if he was truthful. Therefore the second one was lying and the third one was telling the truth by calling him a liar. So he's a tarsal.