So, there are some unused enemies in Phantasy Star II.
The least significant is the Vanleader, which is between a Van and an Aerotank. It was likely left out by accident.
Then we have two enemy groups that never had graphics developed for them. You can read more about them here: https://tcrf.net/Phantasy_Star_II#Unused_Enemies
What do you think about this? It seems pretty interesting to me.