Try talking to it

Lana: I'll try talking to it... But I must say, it sounds like a terrible plan!

Ranvi: Just do it, there is not try! Remember what Master Yoda always kept saying!

Lana: Fine, here goes nothing...

The Rancor is still busy chewing the poor creature as you get closer to it. You try not to "scare" it, with any sudden moves. When it sees you, it stops eating and tosses the corpse aside. You stop where you are and do not look at its eyes. Focusing on its mind, you attempt to talk to it.

Lana: Okay Rancor, I come in peace...! There is no need for anybody to get hurt, alright...? I must say, this feels incredibly silly right now...

It doesn't react in any way. Its breathing is slow, there is no sign of any aggressiveness. You make a few steps towards it, when it suddenly stands up and lifts its arms in the air above himself. You halt again, and put one of your hands on your lightsaber and the stretch the other towards him.

Lana: Sorry, sorry, I didn't mean to offend you by any way! I just want to talk, okay...?

He lowers his arms, as if he understood what you were saying.

Lana: Good, thank you, you are an intelligent creature! There is no need for ****, keep your arms by your side, just like that...!

You make a few more steps, you could even touch the creature itself now. You place your hand on its belly. Its breathing slows, it allows you to pet it, almost as if it wasn't one of the deadliest creatures in the galaxy.

Lana: Good boy, you aren't as fierce as they say...! Now, allow me to help you. I am sorry to say, but you are causing a lot of problems here and...

The Rancor roars and lifts its arms in the air again, as if it was about to crush you.

Lana: No, no wait, I didn't mean that! You aren't the problem, the problem is that you aren't at home! It's natural that you are hungry and big and you just occasionally redesign the local natural habitat...!

It returns to its previous state and doesn't crush you luckily! As if he was listening to you.

Lana: Alright, cool, please, try keeping your arms like that! I know you are a strong one, don't kill me just yet, please! So, here is what I was about to say... I could transport you back to your home world without any trouble, IF you were allowing me to do so...! You could be a happy little Rancor again on Dathomir, Felucia or wherever you are from! There will be no pain, I promise, you won't feel a thing! You just close your eyes and when you open them you are back at home! What do you say?

It doesn't react in any way, yet neither does it attack, so you guess your talking is sort of effective. You have a stun mode on your blaster, but as you switch it and it clicks, the Rancor roars again, tossing you away.

Lana: Well, so much for diplomacy...!