(Try hitting Ctrl+Alt+Shift+H in SL
Hippo originated as a beta discussion about a petting zoo in Second Life, Hippo was eventually chosen, and became wildly popular.
There have been several Hippo creations, as it had become adopted as a mascot for Second Life.
Hippos, a refrence to a Linden toy that still floats about to this day.
Ask an old Linden for more infomation.
Looking up the members of the Second Life Mentor group in find will cause (Hippos) to be displayed instead of (waiting). Seemingly no other group does this (Even Live Help).
Hippos were also the name of a Linden created matchup system, since removed, some people may still have the old accessories, though presence is severely limited after the removal of telehubs.
A Hippo art project was created by Altruma Linden for the infohubs that replaced telehubs.
Linden Lab has a hippo soap dispenser in the office rest rooms.
: This no longer works. The exact date I am unaware of. -NilesArgus