Due to genetic similarities Goolime eggs strongly resemble Muckle eggs. However you will never find a Goolime egg in the sewers.
Goolimes were created as a byproduct of SAR Center research into Muckle physiology after their sudden appearance in the sewer system. Scientists at the SAR Center wanted to determine if there was any way to fix some of the errors in the Muckle's genetic code and give it the ability to hold a more stable form. Attempts to fix these errors did not end as the researchers predicted. Instead of producing a more stable Muckle a new species was created, the Goolime. Goolimes are able to form complex and stable shapes, holding these shapes for hours at a time. Despite their unintended creation the SAR Center calls the creation of the Goolimes a success.