Great Dane Pitbull crosses will vary in appearance from one puppy to the next based on what %Great Dane:%Pitbull is present and which genes are dominant. The trend seems to be more towards the Dane in appearance. She is usually a very large (naturally), long and lean dog without the large, floppy Dane ears. The coat will be short and smooth like both parents.
Great Danebulls are fairly smart, however, obedience training should be started as early as possible. This is a whole lot of dog that can end up being too much to handle if left to run the house. Dominant, firm and consistent commands are necessary, if you can't do that--learn to do it! Early socialization will also bring out the best in their loving, affectionate natures and allow them to be the perfect member of a household with kids and other dogs. This type of hybrid may have some protective instincts and alert enough to be useful, however, they won't bark incessantly.
A well socialized GDB is friendly, maybe overly friendly; their happy curiosity to, say, a cat might be a nuisance and a happily wagging large tail may batter a visitor. Don't be off put by the reputation of large dogs because, as the saying goes, they are as nice as those that raised them. This breed is an attention hog and will love to give it to you as well; they will cuddle with you at a moments notice and prefer not to be alone.
Finally, although many Great Danes are known for being couch potatoes, the Great Danebull will need an hour or so of daily outdoor time due to the Pit mix. A large home with a yard is ideal for this breed unless. Long walks, hikes, jogs, trips to dog park and games with toys are all options that will please your best friend.