What

The Whats are a humanoid alien species whose language is only composed of the word "what."

History
They conflict with the Hey alien species who want to destroy the universe with their weapon, the Big Nothing. As the species is easily terrified, they learn to fuel their ships with fear. Years later, a group of Whats dress as Greys to kidnap the Tick and his sidekick Arthur, whose moth costume makes him look like a Hey. The mission’s interpreter informs the Tick of the Hey’s plan to destroy the universe by inserting a black hole into another black hole, while a What interrogator deals with Arthur until he finds out that he is not really a Hey. The What ship’s long-range sensors alert the ship that the Heys most devastating weapon, the Infinity Ball, has followed them for light-years even though they had thought that it had lost their trail. Arthur fuels the ship with his fear of the What interrogator until they travel at the "speed of lint" to the Hey mothership.

Behind the scenes

 * The species only appear in The Tick's second season episode: "The Tick vs. The Big Nothing." The episode does not specifically identify the species as "What," but the DVD subtitles state "speaking What language" whenever they converse. Additionally, this parallels the Heys' manner of self-identification.