So far there is no official evidence that the Universal Slug exists, and that it's only a rumour.
Trivia
- Redhook says this slug is non-existent, but than again that's what he also said about Fusion Shots, Vitalis Crystals and the Energy Elemental Slug.
Fans' Theories
- The Universal Slug was made by all 5 Elemental Slugs as the main slug of all Slugs. It is a Guardian Slug originally ,so powerful that it can travel to a different universe and still porotect the Guardian Portal but this is still just theories.