Twenty-One, or 21, is a character that is made of 21 blocks. She is voiced by Emma Tate.
Twenty-One originally appeared as literally "Twenty+One". Most fans argued that it wasn't official. This theory was correct. Twenty-One wears camping luggage and a green tyrolean hat with three rainbow coloured "feathers", because she is 3x7. She wears a stepmask because she is the 6th step squad, and two boots, apricot and red.
- I Can Count to Twenty (compound)
- Twenty-One and On (compound and figured-out)
- We're Going on a Square Hunt (compound and figured-out)
- The Big One (compound)
- More to Explore
- How Rectangly!
- The Team Factor
- Hidden Talents
- Making Patterns
- Club Picnic
- Too Many Threes
- Circus of Threes
- Figure It Out
- Steps Versus Squares
- One Giant Step Squad
- 100 Ways to Leave the Planet
- The Treasure of Hexagon Island (debut of "Captain Hexbeard" alter-ego)
- Total: 15 (figured-out) 4 (compound)
TSRITW's design is a skeleton.
Arifmetix's design is swamp green with dark green lips, limbs and teardrop eyes. He is called Camoblock (camouflage) and can make a rainbow transformation to surprise his friends.
MDZ’s design is rainbow and 3 blocks wide (7x3).
Tungster's design has orange limbs and orange goggles.
Mr. Yokai's design is a robot who has many robotic uses. Mainly robot vision and bringing out ball launchers.
thatninjaw's design is a 3 x 7 rectangle, but with a red block on the third h\wide block.
Twenty and One
- 21 was the first Numberblock to have more than two eyes and one mouth.
- They were also the first Numberblock to have two faces.
- The fact that the 21 in "I Can Count to Twenty" is just 20 and 1 conjoined reflects how the Alphablocks form digraphs and trigraphs in their show (For example: Q conjoins herself with U to form the digraph "qu"; H, with C, S, and T, form "ch", "sh", and "th" respectively; I, G, and H form the trigraph "igh"; two O's coinjoin with each other to form "oo", etc.).
Twenty-One's own character
- Twenty-One is the first Numberblock to exceed Twenty.
- She is the second character to have a permanent step squad mask. The first being Fifteen.
- One, Three, Six and Ten had step squad masks in Step Squads, but they weren't permanent.
- Twenty-One is the first multiple of 7 to be female. The 2nd is Twenty-Eight, and the third one is Forty-Nine.