"This giant slug was created by the Ptolemaic Army, using data stolen from the Regular Army. It moves nimbly despite its gigantic size." - MSD info
This gigantic slug was created by the Ptolemaic Army as a prototype, using the stolen data about the Metal Slug tanks.
Metal Rear MK I: Found in Metal Slug 5. This is the original version.
Metal Rear MK II: This variant only found in Metal Slug Revolution, it has the same attacks but different style, also with improved armor.
This gigantic slug attacks by firing its oversized Vulcan, main cannon, or performing a wheelie and crushing the player beneath its enormous treads. Metal Rear can crush an SV-001 and destroy it instantly, even when it is idle and unused. Its armor is very thick and during the battle POWs aid the player by providing Heavy Machine Gun, Rocket Launcher, or Grenades. While riding SV-001, the player may avoid being crushed by jumping before Metal Rear attempts to crush the SV-001. During Metal Rear's second phase, which is reached when Metal Rear receives sufficient damage, Metal Rear performs a wheelie, moving towards the player slowly while shooting constantly from its Vulcan.
In Metal Slug Revolution, the MK II moves faster, while continuing to use its Vulcan, main cannon, and wheelie in an attempt to crush the player. Now however, its Vulcan fires a spread of 4 bullets and its main cannon fires rapidly in the direction the player is standing (up to 8 shells total). It will also occasionally run up to the player in an attempt to crush them, and sometimes call a plane (possibly a Hairbuster Riberts) to drop parabombs or support soldiers.
- In the game, the most common way to battle it is by using the SV-001 because using the SV-001 makes the battle easier for players.
- For veteran players of Metal Slug or for those who are looking for a more challenging match against Metal Rear, a few are always choosing the Slug Gunner path to battle it head on.
- For some reason, instead of a cannon shell just like the SV-001 uses, Metal Rear fires a fireball from it's cannon instead.
- In Metal Slug Defense, before the 1.19.0 update, Metal Rear is the toughest unit in game , with 18750 HP at Level 30, before its record being broken by Brain Robot and Rootmars.
- In the same game, before the 1.30.0 update, the BGM used while battling Metal Rear is "Heavy African". This was eventually fixed as the BGM used is now "Fierce Battle".
- Metal Rear is also the second toughest and second most expensive unit in the Ptolemaic Army in Metal Slug Defense.
- Metal Rear also appears in Metal Slug Attack as a playable unit requiring x80 parts to unlock. Parts can be found for this unit in Attack Stage: Elite 14-5, or by using the Medal Crank.