From the Super Mario Wiki
Oerlikons are purple relatives to Spinies found only in Super Mario RPG: Legend of the Seven Stars. They are found in Barrel Volcano. They are a color swap of Spikeys and Spikesters, and are bipedal Spinies. They are the strongest sub-species of Spikeys.
Oerlikons are most likely named after the Oerlikon 20 mm anti-aircraft gun, with the enemy's spikes blocking Mario's jumping attacks being equated to air defence in a way.
Names in other languages
|From ｢うに｣ uni meaning "sea urchin", and ｢兵｣ hei, which means "soldier" and was also used in Spikey and Spikester's Japanese names.