Being the sign of the twins, Gemini needs a dog that can play to both their fun and serious side. Don't let the bad reputation surrounding Pit Bulls turn you off, because these sweet and cuddly pups make great companions for Geminis. Speaking to the serious part of the Gemini, Pit Bulls are known for being strong protectors for their family and are incredibly intelligent and willing to be trained. Since Geminis often change their mind, they need a dog that can be their rock through those changes.