Clockwork is a ghost who is a Master of Time. He's from the series, Danny Phantom as a neutral character. His 1st appearance was in the episode, The Ultimate Enemy.
In Danny Phantom
Clockwork made his 1st appearance in the mentioned episode. There, he was instructed by the Observers to kill Danny Fenton/Danny Phantom due to the fact that Danny would create a future that would cause his evil self to destroy the planet. At first, Danny thought that Clockwork was his enemy, but that later turns out as being not the case. As it turns out, he's helping Danny to make good decisions about his future. He was key in defeating Danny's dark future self, Dark Danny, and owing the Fenton Thermos containing hin. Clockwork alsk made another appearance in the episode, Masters of Time.
In The Alliance
Clockwork will appear in the final 2 episodes of The Alliance of Super Girls fanon. His role would be the same, only this time he warns Margo not to unleash Pandora from her prison, Margo disreguards his warning and does so anywasy as a way to get a sapphire she had. In the final episode, Margo seeks Clockwork's help to defeat Pandora as well.