Z is a large letter "Z" encountered by the unicorns in Charlie the Unicorn 2.
Charlie the Unicorn 2 Edit
The unicorns encounter the Z on their way to the temple of the banana king. When they see it, the blue and pink unicorns exclaim "Z" and begin to speak to it in a foreign language. At one point, they appear to anger it, causing it to shoot a laser at Charlie. When blue and pink finish talking to it, it begins glowing red and making eerie humming noises.