An eccentric Jupiter is a Jovian-like Planet that orbits its star in an eccentric orbit. Eccentric Jupiters may disqualify a planetary system from having Earth-like planets in it because a massive gas giant with an eccentric orbit may remove all Earth mass planets from the habitable zone.
To date, approximately 7% of all stars have an eccentric Jupiter (e > 0.1), making Eccentric Jupiter's more common then Hot Jupiters.
Out of the more than 200 extrasolar planet discoveries (as of 2006), 15 planets have high eccentricities (e > 0.6).
The typical exoplanet with an orbital period greater than 5 days has a median eccentricity of 0.23.