Complete drop list for Fur Burrow adventure in Castle (K or Q):
1 or 2 gems
+
9, 18 or 27 energy
+
2 Faeries Building Pieces among Blocks, Beams or Pastes
+
0, 1 or 2 items among Floral Glow, Vital Extract and possibly some related stuff
Obviously, considering drops for other adventures, it is not worthed at all.