The Storm Clouds take the form of gray thunderclouds that constantly emit purple lightning.
In gameplay, the Storm Cloud can only be obtained at random from Item Boxes by Shadow and Vampire Shadow. As with all other Items, Metal Sonic can also use the Storm Cloud if he uses the Steal Item to steal it from the aforementioned user.
When used, thunderclouds will be dropped some distance ahead of the user's current location on three of the lanes that the user is not currently on. Touching the lightning emitted by the clouds with a playable character (including the user) will cause them to get zapped by an electric attack, which destroys a random power-up in the playable character's inventory, inflicts damage, and temporarily paralyzes the playable character. The paralyzing effect of the Storm Cloud can also be extended for each individual user by levelling them up to levels 4, 10 and 16.
Unlike most other Trap Items in the game, it is not possible for the player to dodge the Storm Clouds by jumping through them. They must instead slide underneath them or move away from their lane.