Claudus is the original Lord of the ThunderCats and Lion-O's father. In the original series he was seen in flashbacks and was depicted as a wise and old King. He was blind but played an instrumental part in ensuring the ThunderCats survival, and in the process lost his life.
Although the 2011 version of Claudus would also lose his life as he ruled as King of the ThunderCats he was depicted slightly younger than he was in the original series. Like the original series we do see Claudus through flashback sequences but he also appeared in 'real time' at the beginning of the series. In the 2011 series he was still depicted as experienced and intelligent was also seen as a formidable and intimidating warrior. Unlike the original version, in this series he was depicted as both the father figure of both Lion-O and Tygra.