Scorpius
From Sonic Retro
Scorpius is a boss from Sonic Spinball, found in Toxic Caves. He has a scorpion like body and a head designed to look like Robotnik. His tail is immune to attacks and the body is the only vulnerable spot.
Attack Pattern
Scorpius will turn his tail back and forth, dropping acid that will repel sonic down into the only ways into his area. After accessing his area, sonic must jump into the area between Scorpius' tail and his body, which will cause him to rebound multiple times. After taking enough damage, Scorpius' tail will fall off, leaving Scorpius defenseless. Note that if you manage to hit all the slots above Sorpius, you will do heavy damage to him.