Carracosta

Carracosta is here, and it's.. not really doing much. Low attack holds it back from any sort of viability, as does the fact that Water and Rock are both occupied by some very powerful competition means that this isn't a Pokemon worth utilizing.

Best PvE Offensive Moveset

• Go for Water Gun and Surf for maximum utility on Carracosta
• Rock Throw and Ancient Power at least have matching types, which is better than nothing... marginally. 
• Body Slam should be TMed away

Best PvE Defensive Moveset

• Rock Throw is the best Fast Move option for defense, and it pairs well with Surf or Body Slam
• Water Gun is a sub-par defensive Fast Move option  
• Ancient Power is a good move, but the fact that it shares a type with Carracosta's best Fast Move is a bit of a liability, as it makes it easier to hard-wall this ancient sea turtle.

Water Gun has solid damage and energy generation, and lets you deal super effective damage to things like Stunfisk. Rock Throw trades in some of that energy generation for a ton of fast move pressure, which can be incredibly useful in some matchups. No matter which fast move you run, you'll want to run Body Slam and Surf. Not only are they solid moves in a vacuum, they're also not Ancient Power (which is a bad move.). Liquidation is largely redundant since Carracosta already gets Surf.