General Irritability:
* Grumpy
* Irritable
* Peevish
* Cross
* Grouchy
* Crabby
* Surly
* Ill-tempered
* Bad-tempered
* Testy
* Fretful
More Intense Anger:
* Irascible
* Choleric
* Hot-tempered
* Bilious
* Cantankerous
More Playful/Humorous:
* Curmudgeonly
* Grumbling
* Whiny
* Moaning
More Specific to Age:
* Senior moments (for older people)
* Fussy (for babies or children)
The best word to use will depend on the specific context and the tone you want to convey.