Beware-the-batman Wiki
I used to think I was a monster because of how I looked. But you're only a monster if you let yourself become one.
Metamorpho/Rex Mason
Screen Shot 2013-11-24 at 12.34.27 AM
Age 30's
Gender Male
Enemies Simon Stagg
Batman (formerly)
Friends Sapphire Stagg (lover)
Job Security Guard (formerly)
Villain (formerly)
Hometown Gotham City

Metamorpho, formerly known as Rex Mason, is a character appearing in Beware the Batman, first introduced as an antagonist in the episode Toxic and became a hero in the episode Monsters.


A security guard working for wealthy industrialist Simon Stagg, Rex Mason fell in love with Stagg's daughter Sapphire. They met in secret as Rex was sure that her wealthy, elitist father would never accept him as a worthy son-in-law. However, Stagg found out about their relationship and vowed to arrange a "accident" for Rex. Disguised as an intruder, he tricked Rex into an experimental chamber and flooded it with a mix of experimental chemicals. Though Stagg had intended for them to simply kill him, these chemicals radically changed Rex's cellular structure. He slowly mutated into a monstrous form composed of many types of elemental materials including rock, metal, and ice. Rex vowed vengeance and attacked Stagg but was tricked into the same chamber that created him by Batman who tried to cure Rex but failed. Sapphire sadly confessed that she couldn't continue to be with Rex as he was now and Rex, heartbroken, broke the ventilation system in the chamber and faded away to vapor only to be seen reconstituting himself in the sewers sometime later. In the episode Monsters, Rex resurfaced and took up residence in an abandoned church in Old Gotham and fought crime as a vigilante people dubbed "The Golem of Old Gotham". He aided Batman and Katana in defeating the armored thugs sent by Sapphire Stagg and took on the codename "Metamorpho".




Metamorpho stands at roughly seven feet tall and his body seems to be a rough patchwork of different materials ranging from stone, ice, metal, concrete, and plastic. Metamorpho can shape his body, usually his hands, into different weapons and tools including blades, clubs, maces, and shields. He can also change the consistency of his body from liquid to gaseous. Metamorpho also exhibits the ability to control his body heat, able to make himself either hot enough to melt metal or freezing cold. He also absorbed the power of electricity from Batman's stun batons and gained the ability to project lightning bolts.

Powers and Abilities[]


  • Elemental Transmutation
  • Elasticity
  • Elemental Mimicry


  • Unlike his previous incarnations, in this version, he is a villain instead of a hero, in his first appearance.
  • Katana's suggestions for his codename included Muto, Changifarian, and Mr. What-is-that.
  • This is his third animated incarnation, first in Justice League and second in Batman: The Brave and the Bold.
  • He is the second mutant that appears in the series. The first being is Mr. Toad.
  • He is the first mutant who became hero.