Each of these creatures is a blend of two different pokémon: CETITAN and FALINKS, CONKELDURR and HOUNDSTONE, HITMONLEE and METAGROSS, HOOTHOOT and PARASECT, and MUDKIP and PIDGEY. After identifying the pokémon, the key to solving this puzzle is noticing that each pair of pokémon have names that are the same length.
Each pair of pokémon also share exactly one letter which is in the same position for both (i.e., both CETITAN and FALINKS have an I in the fourth position). The pairs of pokémon are also all different lengths, one set each for lengths from six up to ten letters. Ordering the matching letters by length of the pokémon names give the answer DITTO.
- MUDKIP/PIDGEY (6 letters) – D
- CETITAN/FALINKS (7 letters) – I
- HOOTHOOT/PARASECT (8 letters) – T
- HITMONLEE/METAGROSS (9 letters) – T
- CONKELDURR/HOUNDSTONE (10 letters) – O