Excelsus (エクセルすゝ, Ekuserususu) is a male Brontosaurus of the Secret attribute belonging to Alvin Douglas, acting as his faithful companion. He is the first ever dinosaur to be discovered by Alvin, and thus was made his main dinosaur, normally being either the first or the only dinosaur to be summoned into combat. He was also the first dinosaur ever to activate within the dimension of 0001, where Alvin resides; utilizing the stone that allowed Alvin to understand Excelsus's emotions, Excelsus and Alvin understood each others' intentions and returned to his card form, resulting in him being within Alvin's care.