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. 
• Focus Blast isn't very useful.

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. 
• Focus Blast takes too long to charge up to be useful in most scenarios.

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.