J is the tenth letter in the Alphablocks gang.
J is voiced by Teresa Gallagher.
She is a powder blue and white Alphablock including an orange 'beak', since she thinks she is a blue jaybird.
J is cheerful and thinks that she can fly like real jaybirds do.
- Alphablocks (first appearance)
- Fox (sound only)
- Zap (sound only)
- On (sound only)
- Frog on a Dog
- The End
- Band Together
- Letters to Santa
- Making Friends (last appearance)
- Crossover (image only)
- "Jaybird! I'm a jolly J."
- "Jolly nonsense."
- "Jumping jellyblocks!"
- J is the second of the 5 blue characters.
- J appears in 18 episodes of the series.
- J's letter means 19 in Vigesimal.
- There is a running gag in the series that J sings horribly, such as in ABC, although other episodes show her singing decently.