So, we finally know how old Cucumber is:
Quote Originally Posted by gigi's tumblr
Here’s the updated vague age guide:

Slightly Younger Kid Group - Almond, Peridot, Cosmo
Kid Group - Nautilus, Mandolin, Panpipe
Not 9 Group - Cucumber
Younger Adult Group - Saturday, Carrot, Parfait, BLTs, Piano, Bakerette sisters
Yes, He’s an Adult Group - Bacon
Adult Adult Group - Cabbage, Cordelia, Lute, Cymbal, Caboodle
Not as Old as the Mustache Makes Him Look Group - King Kelp
N/A?? - Dream Oracle, Nightmare Knight, Disaster Masters