Does anyone know where one can get the Blue Bird / Bluebird Minion from?

Someone said it is a reward from the 30 day Veteran Bonus but it is not listed there (only says Cursor Minion and Appearance Change item).
Is this incorrect or are there secret veteran rewards for each stage that are just not announced officially (to make it somehow more of a surprise or something)?

I'm annoying my whole FC with that silly blue bird because I really want it.

So, if anyone can help, I'd appreciate it a lot!! Thank you.