They are devoted, loving, loyal, cheeky, intelligent and full of mischief.
From Wikipedia, the free encyclopedia:
The Griffon is known to have a huge heart, and a strong desire to snuggle and be with his or her master. They display a visible air of self-importance. A Griffon should not be shy or aggressive; however, they are very emotionally sensitive, and because of this, should be socialized carefully at a young age. Griffons should also be alert, inquisitive and interested in their surroundings.
Griffons tend to bond with one human more than others. In fact, Griffons are very good with children provided they are not teased. They are not very patient but do love to play. Griffons tend to get along well with other animals in the house, including cats, ferrets, and other dogs. However, they can get into trouble because they have no concept of their own relative size and may attempt to dominate dogs much larger than themselves.