Update 13 introduced the water-themed Hydroid. While his crowd control (like "Tentacle Swarm") was visually impressive and useful, farming his parts from Vay Hek was notoriously difficult at launch.
Some of the best visual work in the game's early years.
Excellent for farming credits and resources early on.
The boss fight required for Hydroid parts was often criticized for being tedious.
Essential items like Stance Mods were initially very rare and hard to farm.