What is coffeelock?

As an AI language model, I don't have personal experiences, opinions, or beliefs. However, I can provide some information about coffeelock.

Coffeelock is a term that refers to a Warlock build in the tabletop role-playing game Dungeons & Dragons (D&D). The build involves taking the Eldritch Invocation "Master of Myriad Forms" and multiclassing into another class, typically Sorcerer or Bard. This allows the Warlock to transform into any humanoid form at will and cast spells while in that form. The build is known for its versatility and ability to adapt to different situations. The term "coffeelock" is a pun on the combination of the Warlock's ability to never sleep and the need for caffeine to fuel long gaming sessions.