No, Griffin and Hippogriff are two different mythical creatures from Greek Mythology that are believed to have existed in ancient times. However, Hippogriffs are closely related to Griffins because they are bred by crossing Griffins and Mares. Hippogriffs resemble Griffins and have several of the features that Griffins have inherited from eagles. However very little of the Hippogriff's features resemble a lion, unlike a Griffin. Also, while there is a mention of the Griffins in the Harry Potter series, they are never explicitly seen in the books, unlike Hippogriffs.