Play with Hardcore, who came with the latest update. We are not perfectly sure how this mystery character can be unlocked. It's likely that you have to kill the BBQ Grill Boss at the end of a shoot skies "level". Maybe there is a second condition needed. Please tell us about your experience with the unlock! Thx to everyone who helped with suggestions (Steffi, CK1, gadger, Rhino, Ken Ash...)!
Play as the Yeti. The Yeti is an old Shooty Skies character, that was already in the game befor the Munchable Madness Update came out. During playing a wooden box will occur with a popsicle inside. Collect the popsicle to unlock the secret character Popsicle, P.I.
We unlocked this secret character with Hardcore, but it also reported that this mystery character can be unlocked with other new Characters from the Munchable Madness Update (Cutie Pie, Hardcore, Jabba The Hot, Sweet Beets, Lil' Softie, Tootnramen or Great Shakers). Die at a score of exactly 10 to unlock this secret character.
It looks like this mystery character can be unlocked with any of the new Characters from the Munchable Madness Update (Cutie Pie, Hardcore, Jabba The Hot, Sweet Beets, Lil' Softie, Tootnramen or Great Shakers). We are not perfectly sure whats the exact unlike conditions. Probably you have to kill a certain enemy like the toaster. Nevertheless it doesn't seem to be too difficult, just play a little bit.
Most probably you have to play with Jabba The Hot and perform round about 6 charged attacks (do not press the screen for some time to charge your weapon). Jabba The Hot looks quite similar to the secret character Insanity Pepper so this method for unlocking him sounds reasonable.
Play as Lil' Softie (or Hardcore, Jaba The Hot...) and collect the boxes with the ginger breads inside. You will need round about 20-30 ginger breads to unlock the new Shooty Skies Secret Character Ginger.
Unlock Guide for all Secret Characters in popular mobile games