If your little brother wants a pet griffin, you should probably try to talk him out of it. A griffin is a flying, eagle-headed lion with sharp talons. (Luckily for you, griffins aren't real.)
The mythical griffin — also spelled gryphon or griffon — dates as far back as 3000 BCE. Some griffins have the front talons of an eagle, like the griffins that appear on shields or coats-of-arms — they were often used this way, since the combination of lion and eagle was seen as being especially brave and strong. Griffins appear in literature ranging from Rumi's ancient Persian poetry to the Harry Potter books. The word's Greek root is gryps, "curved."