Candy was introduced in the following 'What's New' page, ported over from the old Improbable Island wiki. Link.

That page links to this URL, but so far there's not much here. There is however another Candy page at the following link. Link.

Per the What's New page:

Candy! – As of Oct. 2014

Candy is this new thing. It's like cookies! Except, individually, they're much smaller. They give you 5% stamina, each, and give a minor percent buff to your attack and defense. They also stack with each other! With a total of 30 different kinds, each buff lasting 1000 rounds each, they end up giving a MASSIVE buff! You can get them in the Hunter's Lodge. More info here.

PLEASE NOTE: this does not appear to be 100% accurate anymore. Please see the linked items:Candy page for more up-to-date information.