Why is Zezima so famous?

Zezima has many claims to fame such as being the first player to get every skill to level 99 or the first player to get to level 99 Slayer. He slipped on the hiscores after leaving RuneScape around the time Summoning came out and not getting it to level 99.

What does Zezima mean?

M Mighty, your inner strength. A Admirers, and all that you have!