Dragalge

Dragalge is an interesting addition to Pokemon Go, featuring a Dragon/Poison typing and defensive stats. While this may not be useful for raids, it does make Dragalge a potential candidate for gym defense thanks to its resistance against common Fighting-type attackers. Whether Dragalge is actually worth the resource investment is another story however. 

Best PvE Offensive Moveset

• Dragon Tail + Outrage is the strongest moveset and benefits from STAB. 
• Acid + Gunk Shot is passable if no other Pokemon are available. 
• Water Gun has no use.
• Hydro Pump is stronger than Aqua Tail, but consider actual Water-type Pokemon instead. 

Best PvE Defensive Moveset

• Dragon Tail is the strongest against neutral attackers due to its high base power. 
• Acid isn't particularly impressive, but can hurt Fairy-type attackers who forgot about Dragalge's Poison-typing. 
• Water Gun is too weak for defense.
• Aqua Tail can be used frequently as a 3-bar move, and also hurts Ground-type attackers.
• Outrage is a bit slow for defense, but hits hard if it isn't dodged. 
• Hydro Pump might not be accessible before Dragalge faints, but it's hard to dodge.
• Gunk Shot is a slap in the face for Fairy-types if it connects, partly due to its animation. 

Dragon Tail is superior to Water Gun due to the significant differences in damage output. Acid is a poor move. 

Aqua Tail costs the least amount of energy, and can be used frequently to pressure shields. Outrage hits hard and demands a lot of energy, but is cheaper than Gunk Shot and Hydro Pump.