In 2003, there were two crossover one-shots with the ThunderCats; the first (May 2003) was published by Top Cow and the second (July 2003) was published by Wildstorm.
Tag: ThunderCats
Thundercats (2002)
Reclaiming Thundera (written by Ford Gilmore with various artists contributing), published between 2002 and 2003, formed a series of loosely connected “episodes” that saw Lion-O continue his struggle against Mumm-Ra and The Mutants.[8] A major plot point was the slow corruption of WilyKat by Mumm-Ra, which would play a major role in later storylines. After another fateful battle with Grune, Lion-O entered the Book of Omens to begin his training and claim his rightful place as Lord of the ThunderCats, but Mumm-Ra uses a powerful spell to keep Lion-O trapped in the book for several years in real time, not “Book” time, and seizes control of Thundera afterwards.
EHT Comics 