Clawitzer

Like many other Gen 6 Pokemon, Clawitzer's release into Pokemon Go is rather unexciting from a timing perspective due to stronger existing Pokemon. That doesn't mean it's a bad Pokemon; if Clawitzer is a personal favorite from other Pokemon titles then feel free to use it in Pokemon Go. Kyogre might get lonely though. 

Best PvE Offensive Moveset

• Water Gun is more suitable for offense, since it benefits from STAB.
• Smack Down is meant for Rock-type attackers.
• Crabhammer is the best charge move for Clawitzer. 
• Water Pulse is a direct downgrade. 
• Ice Beam is good as a secondary coverage option for attacking gyms. 
• Dark Pulse doesn't have much use. 

Best PvE Defensive Moveset

• Smack Down is the best option for defense due to its high base power. 
• Water Gun may benefit from STAB, but its damage output is still significantly worse. 
• Ice Beam is generally best for defense due to its threat vs Grass and Dragon attackers. 
• Crabhammer deals the most damage against neutral attackers thanks to STAB.
• Water Pulse is a bad move. 
• Dark Pulse is decent but doesn't have much use for a Water-type. 

Water Gun is an overall well-rounded move that provides a balance of damage output and energy gains. Smack Down offers strong Rock-type coverage, but lacks STAB and doesn't really suit Clawitzer. 

Crabhammer is not only Clawitzer's strongest charge move, but also ties for the cheapest energy cost, and thus becomes its primary charge move. Dark Pulse provides relatively neutral coverage, while Ice Beam can threaten Grass-types and Dragon-types that Clawitzer may struggle against.