Here are the combos(mixing) that I know:
Ice+Sword=Ice Sword
Electric+Sword=Thunder Sword
Fire+Sword=Fire Sword
Ice+Bomb=Ice Bomb
Electric+Bomb=Electric Bomb
Sleep+Sleep=Ghost
Maximum Tomato+Maximum Tomato=Random Bubble(?)
Chicken+Cherry=Maximum Tomato

Some of these might be of help, some moght be plain rubbish.
Good luck!