Appearance and Personality
"The black-and-white dog was obnoxiously happy and had bright green eyes, one of which was larger than the other. Bob had placed a red bandana around Buster's collar."
Buster is a border collie from the pound, given to Alex and Conner by Dr. Robert Gordon. In chapter 6 of The Enchantress Returns, they find out he is Sir Lampton, bespelled by the Fairy Godmother, in order to keep an eye on them without them worrying.
"A flash of light traveled from the tip of her wand and into the dog's mouth. Buster began barking, but the sound slowly morphed into the sound of coughing - human coughing. "Pardon me," the dog said. "My word, it's been a long time since I've had to pronounce anything."