Elementals

The Elementals are a group of evil masks who have the power to manipulate a particular element and cause chaos across the world. Their only appearance is in Crash Bandicoot: The Wrath of Cortex where they gave Crunch powerful abilities. Dr. Neo Cortex used them as a power source for Crunch when he was brainwashed and still evil. After Crash defeated them they were sealed away in a hibernation state again.

History
Like Aku Aku and Uka Uka, the Elementals were probably powerful witch doctors many years ago who put their spirits into magical masks when they died. After word they had caused massive amounts of damage to the world such as the Ice Age (Wa-Wa and Lo-Lo), earthquakes (Rok-Ko, (Py-Ro?)), and floods (Wa-Wa) as said by Uka Uka. They were then sealed away by the Ancients who are mentioned in the manuel and Crash Bash. It is unclear whether the Ancients used the Power Crystals to seal them away such as in the game or if they were powerful enough to seal them away with their own power. They may or may not be brothers. It is unknown if they are related to Aku Aku and Uka Uka in any way.

Rok-Ko
Quick to anger with a head full of rocks and grumpy, Rok-Ko is the Elemental mask of Earth. He controls such earthly forces as earthquakes and landslides to name a few. He seems to be the most childish of all the elementals, giving juvenile fight threats to Crash Bandicoot. The only witnessed powers he possesses are causing rocks to fall from the sky and protecting Crunch with a rock sphere. He might have a bit of control of fire because when Crunch touches rocks they turn on fire. It was stated by Cortex that the other Elementals are significantly more powerful, making Rok-Ko the weakest mask. He is voiced by Tom Wilson in the English version and voiced by Toshiaki Kuwahara in the Japanese version.

Wa-Wa
Out to flush the world clean and rebuild it as he remembers it, this stick-in-the-mud puddle is the Elemental of Water. He has a militaristic personality, and has a typical American general's accent. His powers (as seen) include transforming Crunch into suspended water, and creating balls of ice. He can also bestow the ability to create energy waves. He is voiced by R. Lee Ermy in the English version and voiced by Kappei Yamaguchi in the Japanese version.

Py-Ro
The strongest and the most evil of the ancient Elemental masks, Py-Ro controls the element of Fire. His temper is known to go off like a volcano when perturbed. He has a somewhat calm personality, that is somewhat insane. He, as expected, has an affinity with fire. He can conjure fire, from the ground or as a wall, and transforms Crunch into a load of smoldering rocks in his form. What's ironic about him is that his voice does not fit his appearance. He is voiced by Mark Hamill in the English version and voiced by Toshitaka Shimizu in the Japanese version.

Lo-Lo
This crazy joker could be a real blast at a party if he didn't always blow the house down! Lo-Lo is the Elemental of Air, and has dominion over the the forces of wind, lightning and atmosphere. He can create electricity and lasers at will, and can transform Crunch into a huge, genie-like entity that can throw electricity. He has a somewhat effeminate personality, and is quite arrogant. He is voiced by Jess Harnell in the English version and voiced by Masaru Ikeda in the Japanese version.

Trivia

 * They share the one game only trait with Von Clutch, Rusty Walrus, Zem, & Zam
 * Out of all of past villains, they never came to Dr. Neo Cortex's "birthday party" in Crash Twinsanity, though this is probably because they were imprisoned at the end of The Wrath of Cortex.
 * It is never established in The Wrath of Cortex how Uka Uka actually freed and woke the Elementals.
 * Py-Ro's name comes from the word "pyro" which is the scientific name for heat.
 * It seems ironic that Lo-Lo is fought after Py-Ro, given that Py-Ro is stated to be the strongest mask. Though, the boss fight for Lo-Lo and Crunch is significantly more difficult. And when the four elements are stated the order is usually Earth, Water, Fire and Air meaning Air is the last one, so the masks are fought on that order and that originally Py-Ro was going to be fought after Lo-Lo.
 * They are well known by Aku Aku and Uka Uka - and know them well as well. They have an antagonistic relationship with Aku Aku as they taunt him.
 * Nothing had been said by Uka Uka in the past about something drastic that Py-Ro had caused. Likely Py-Ro causes fires in areas where great damage could be done, like forests.