Obelius resembles a pteranodon with a long gray head with spikes extending from the top of its beak with razor sharp teeth, a yellow nick, thin light brown limbs with five digits, large crimson wings, a gray abdomen with a port for missiles, a white mane behind the neck with a humanoid head sticking out with red hair and a yellow and purple face.

Obelius is able to fly long distances with its large wings. Its mouth features an ultra sharp beak that can tear apart opponents and can release heat in the form of a beam or flames. It is armed with sharp talons for close combat while its abdomen can release missiles while its face is able to release sonic waves.

Obelius isn't seen much in the first episode except when General Birdler presented him along with General Ligern's Barubari to fight Great Mazinger and is seen again chasing Jun Hono. When Great Mazinger appears, he uses his sonc waves to stun the Great, allowing Barubari to attack him. However, the Great recovers and uses its Great Boomerang to cut Obelius' real face, jump at his back directing him to Barubari, impaling him in the back.