Learn to fear the creepy skele-girl with the purple eye.
10000000000% harder to beat than initial form.
In order to see her final form, you need to kill her mom. Doesn't matter if you kill any other random encounter, just make sure to spare all the bosses EXCEPT Frisk.
She will meet you at the gate to their city (the exit, close to where the game ends) (AND REMEMBER, THIS IS SORTA LIKE THE FUTURE, YEARS AFTER THE MONSTERS HAVE BEEN FREED FROM THE UNDERGROUND.) and she will say, "...Hey. I actually thought we could be friends, even after you've left New Underground." (I'll explain the bad naming later...) She will chuckle for a second, and then say, "I knew I was stupid. When I met you, I felt you could be a good guy. But after what you did, I bet you feel guilty." Then you have the choice to say yes or no.
If yes, she will say, "Of course. Regret always comes when it's too late. Well then..." She will close her eyes, and when she opens them, her left eye will be glowing purple. "How would you feel if I did the same to you?"
Then the battle begins. If you say no, she will say, "I will freaking kill you." Aannnd yeah. If you eat Cinnamon-butterscotch pie in her fight, she will look away for a second and say, "That was mom's favorite. Before you MURDERED HER."
The fight will be similar to Sans', but the attacks are purple and causes much more damage.
This is what shows when you check her:
*Tara LV?? ATK 20 DEF 55
*Almost impossible to beat, unless you're some sort of supernatural being.
When you get to the last five minutes of the fight (that is, if you haven't died yet) she will stop attacking and fall to her knees. She will look at you, crying, and say, "Why did you...? You know dad and I can't live without her...please...just...reset..." And looks down with her eyes closed.
Then you have the choice to spare or kill her. If you spare her, she will say, "You're...sparing me...?" She will slowly stand up. "B-but..." She will close her eyes again, and does exactly what Sans does when you try to spare him in his fight.
If you choose to kill her, you will completely deplete all her HP, no matter what lvl you are. Then she will say, "Huh...well..." Then the sound of when a monster turns to dust will be heard. But instead of disintegrating, only her human looks will disappear. She will open her eyes, stand up, and look at her hands. "Haha...I actually forgot about this. This is my final form. My strongest weapon. Hah...NOW it's a party."
Then if you check her, you will see this:
*Skeleton Tara LV?? ATK 100 DEF 100
*Better start praying she'll have mercy on you.
While you're fighting and you don't get hit, she will start to look more and more scared. In the last few minutes of the fight, she will say, "How...why. Won't. You. Die."
She won't do anything for the next turn, and that is your only chance to land a hit on her. The damage is 10 and only ten. If you deplete all her HP, she will fall down again, and this time say, "Heh...guess that's it for me huh? Well...atleast tell dad I love him..." Then she just dies. She won't turn to dust because she is half human.
And wowie, I did not expect to type anything this long.
