Maybe I found a secret dragon or something, a wyvern which started on lv.2 evolution and has an "apalala" trait (don't know what it does but apparently it buffs skill when placed on buff). I trained it to lv 2/10, it looks it can be evolved to lv.3 (with 9999 stats!!!) but evolve button stays gray even if i have a load of potions and stuff.
The "Stop 100 penguins at the gate" trophy is impossible to obtain, because towers DON'T shoot at penguins when they're close to the exit, and the various area towers (shaker, etc) shoot just slow them for a bit.
Just one of too many bugs.