Mobile

Mobiles are snowmobiles driven by Blues that try to catch Big Blue and transport him out of the screen to safety. Although they have no defense, a Drab will sometimes board a Mobile and fire at any nearby slusher to make destroying it harder than before.

Slush Invaders
Mobiles were not in the movie probably because in the movie they only stayed at Slusher and wouldn't have done much good without snow to drive on.

Slush Invaders: Game
Mobiles will try to get to where Big Blue will land and catch him. When they do, they will try to go off-screen to initiate a game over. Trying to target Big Blue at that state will target the Mobile he's on instead. A Mobile's only defense is to rely on other Blue forces or have a Drab board the Mobile. In Tundra and Slushy Ice Frosting, Big Blue starts aboard a Mobile instead of being kicked by Standrew. In NG+, Mobiles gain a lot more health, and are harder to destroy as a result. Destroying these Mobiles will require the power of a fully upgraded Stick JK to remove a large portion of their health, leaving the rest to a single fighter.

In NG+ mode, this can be one of the most annoying enemies, example: A mobile is with Big Blue, you destroy it so 5 secs later another got Big Blue again, and so...

Trivia

 * Mobiles, along with Toasters are the only enemies on wheels.
 * Mobiles, Azures, and Cobalts are the only defensive enemies in the game.
 * Mobiles and Azures are the only enemies with no attack methods, excluding that certain Mobiles have Drabs on board and Cobalts because, while they don't attempt to attack fighters, still cause damage upon contact.
 * Mobiles are the only defensive enemies that run on wheels.
 * Mobiles don't just appear in snow levels: some are also seen on Luna.
 * Some players have reported winning even with Big Blue riding a mobile.
 * There is a glitch where Big Blue looks like he is still riding on the mobile and stays at that same velocity he was traveling in and stays in that same position. This glitch is also rare and hard to find.Screenshot_from_2013-11-25_14-56-14.png
 * Logically, since Mobiles are built to drive on snow, they should not appear in any levels other than the winter areas.
 * When they are about to go off-screen, use Stick Sean (all upgrades) to pull it behind.
 * Mobiles are the only machines that do not attack in the entire game.
 * There is a weird glitch in where a Mobile may appear in a non snow themed level.
 * They do not appear in Slush Tile Rush.