Mini-Bosses are tougher-than-normal enemy characters who appear part-way through a stage, instead of at the end. Some bosses (or their palette swaps) may later become mini-bosses.
“Shiva' s first appearance was Streets Of Rage 2 as part of the final stage; he must be beaten...Shiva
“Z. Kusano is a mini-boss appearing in Mr. X's elevator in stage 8 of Streets of Rage 2, just...Z. Kusano