Rexon

The Rexon was a second-generation Badnik created by Dr. Eggman in Sonic the Hedgehog 2 for the Sega Genesis.

Physical Appearance
The Rexon resides in molten hot lava, its armored carapace meant to withstand the immense heat of its domain. Its backside (or shell) is indestructible and can be used as a platform, but when an enemy comes near, the head and neck retract from their safe home to spot intruders. Their necks are not 100% stable, so it sways back and forth while they search around. Their plating is light purple and pale blue. The appearance of this Badnik may be an homage to the legendary Loch Ness Monster. When they are destroyed the head and neck detach and are destroyed, leaving only the shell behind.

Attack Pattern
The Rexon retracts into its shell until its sensors indicate an enemy presence. When a target is spotted their neck and head retracts and floats above the surface. Internal heat mechanisms then allow the Rexon to spew dangerous fireballs from their mouths periodically. Despite their intimidating appearance, Sonic found ways to exploit their platform-like shells as a stepping stone to beating them.