The Unira spawns with its spikes retracted. When thrown, it will extend its spikes upon touching a surface, causing it to stick to that surface. When active, it cannot be picked up and opponents that make contact with it are dealt 7% damage and weak knockback. Opponents hit by a thrown Unira while still airborne are dealt 11% slash damage and moderate knockback. An active Unira can be made inactive and vice versa when attacked, causing it to switch between states and receive knockback based on the attack.
Uniras are a race of urchins from the game Clu Clu Land. In this game, they steal and hide the treasure from the underwater kingdom Clu Clu Land, consisting of huge golden ingots. The female balloon fish, Bubbles, sets to retrieve the stolen treasure, confronting the Uniras in the process. They serve as enemies in the game and Bubbles must avoid direct contact with them, as their spikes are able to pop her. Bubbles can stun Uniras by emitting a sound wave, which make them retract their spikes, allowing her to touch them and smash them against the walls of the level to defeat them. If Bubbles defeats the last Unira on screen, another one will spawn from the whirlpools. In SSF2, Uniras serve as throwing items that protrude their spike after they are launched; similarly to how Bubbles could stun them to make them retract their spikes, fighters can directly attack the Unira to make them do the same, allowing them to pick the Unira again.
In certain cases where an active Unira makes contact with another or multiple Uniras, their spikes will continuously extend and retract. This will continuously cause massive damage to anyone in contact with any of the Uniras.