Slime Princess

Slime Princess makes her appearance in "Prisoners of Love" where she is kidnapped by Ice King. She showed a lot of affection to Finn, even going as far as saying she wants to marry him for saving her and the other princesses, or at least until Jake told her that Finn wets his pants all the time.

She has a brief scene in "The Eyes", in which Finn and Jake recount saving her from the Ghost Ship Vortex.

She reappears in "Loyalty to the King" as the first princess to meet and befriend the "Nice King" in the park after misinterpreting his real name.

Appearance
Slime Princess appears to be a small piece of slime. She wears a tiara similar to that of Princess Bubblegum, only the gem in the center is green, while Princess Bubblegum's is blue.

Quotes
"Thank you for saving us Finn."

"And remember when you said you'd vow to marry us to the thing of our choosing? Well, I'd like to marry you."

"Oh, gross! Put me down, PUT ME DOWN!!!!"

"We've all been held prisoner Finn."

"He's held us here for weeks; questioning us about our favorite sports and quirky behaviour. I've tried to tell him as little as possible."