Sir Kirby is a British armored knight action figure with an English accent that belongs to Donny. He often plays the hero in Doc's game "Save Princess Lambie from the ferocious dragon", but not without taking some damage.
Sir Kirby wears knight armor with a red knave-like outfit, goldcrest, blue gloves and shoes and a knight helmet on his head.
- "It is I, Sir Kirby! The bravest knight in all of McStuffins' kingdom!"
- "A true knight always stands tall."
- "An unclean knight will never do! Princess, I beg you forgive me."
- "Thanks to you, Lady McStuffins, I feel like myself again."
- "I feel as though I could hop onto my trusty steed, battle a scary dragon, and save a fair princess."
- "My thanks, good Lady McStuffins. How embarrassing for a knight to be saved by a... (whispering) by a dragon."
- "I am most delighted to be here, friends, as it is my first sleepover party ever!"
- "I do say, this sleepover party is most delightful!"
- "Yes, well, I-I'm not feeling very well at all. I-I feel, um, shaky and sweaty actually."
- "Me scared? Need I remind you that I am Sir Kirby, the bravest knight in all of McStuffins kingdom! Why I have fought dragons, saved princesses and conquered evil kings!"
- "When the darkness fell, I saw something strange, like a--like a scary monster right there."
- "M'lady, you are the kindest and bravest princess I know!"
- "You know, it's not too dark. I can see what everything is. That's not a monster. It's a chair! I think my DarkWillies are much better."
- "May I have this dance, m' lady?"
- "It's just a flesh wound!"
- "You cannot just knock on a knight's armor."
- “Quite so lady Lambie, for you are one of a kind, the best kind.”
- Sir Kirby is afraid of the dark.
- He has a dad and sister, who have both won a derby.
- His Grandfather won the Battle Of Toyfall