Bosses are the powerful creatures at the end of an area that you have to fight and defeat in order to proceed to the next area. When defeated for the first time, bosses usually unlock a new boost towards the end of the fight. When a boss is attacked after the initial success, a victory still gives you MinoCredits. However, fighting a Grubling Candy or a catch-able Mino located on a boss-spot will not give you credits.
Forest Boss: Foreman Grubling, Level 15
Beach Boss: Triple Grubling, Level 7, or Belooba, Level 9
Sandbar Boss: Water Grubling, Level 11, or Cupaw, Level 6
Jungle Boss: Earth Grubling, Level 15, or Vertris,Level 9
Waterfall Boss: Water and Earth Grublings, all Level 10,or Alakin, Level 9
Note: Sandbar, Jungle and Waterfall bosses' levels seem to be from an earlier version. So do Alakin and Vertris' levels. Please fix them.
Desert Boss: Fire Grubling, Level 14, or Purpus, Level 18
Cave Boss: Electric Grubling, Level 15, or Ersa, Level 15
Prairie Boss: Fire and Electric Grublings, both level 19, or Scitch, level 17
Mountain Boss: Fire, Water, Electric, and Earth Grublings, all Level 20
Dune Boss: Lava Grubling, Level 27