There at least four bands named Hyena.
1) indie electronic / dance duo Mike Cooper and Bryan Stratman from San Diego, California, who have just released their self-released debut We See You.
http://www.wearehyena.com/
Hyena on DeliRadio.com
2) an Italian rave/techno dance duo most famous for the song "Bach is Back." The female vocalist Morena was the original core of the band, and in 1994, she started collaborating with African rapper Nana (Abrokwa?). Bio in Eurodance Encyclopaedia
3) an italian electronic producer involved in breakcore , darkambient , digital-doom.
official page
hyena myspace page
4) a belgian thrash metal band from the Dender area
http://profile.myspace.com/index.cfm?fuseaction=user.viewprofile&friendid=153168475
5) an indie jungle soul group from kennebunk, maine.
http://www.myspace.com/hyenahaha