What is the name of the blue, wish-granting creatures?

The blue, wish-granting creatures are called Meeseeks. Each one is summoned from a Meeseeks Box to complete a specific task for the person who created it.

Meeseeks are usually powder-blue humanoids with cheerful voices and a strong desire to finish their assigned job. Once the task is completed, the individual Meeseeks disappears. Their existence is portrayed as painful, so an unfinished assignment can cause one to become increasingly desperate, unstable, and dangerous.

The creatures first appear in the season-one episode “Meeseeks and Destroy,” which originally aired in 2014. Jerry Smith’s seemingly simple request to improve his golf game becomes a disaster when repeated Meeseeks fail to solve the problem quickly. Beth and Summer, by contrast, complete their requests with much less trouble.

The common mistake is calling them genies. Meeseeks can help fulfill requests, but they are not magical wish-granters with unlimited power: they are task-oriented beings whose abilities have practical limits. “Mr. Meeseeks” is the usual individual name, while “Meeseeks” refers to the species or group.