In general, Guilala resembles a large, birdlike creature with a bulky, muscular body and strange antennae on top of its head. Guilala's head is silver with pink eyes, while his body is dark grey. The tips of his antennae are bright gold. Guilala also has a series of horns on the back of his head which curve upwards, and his forehead has a strange, periscope-like appendage rising out of it, which may be a third eye. Guilala's feet are large, and have well-developed claws. On the front of each of his thighs, he has wave-like ridges which run vertically down towards his shins.
A species of kaiju created by the explosions of stars, Guilala was made out of a special form of condensed energy. This energy is normally found in little contained spores. An unknown alien race once attached spores to a space ship from Earth. One spore was carried back and the Guilalium was taken off. The spore broke open and Guilala came out and grew to monstrous proportions! It destroyed most of Japan in the search for energy. Guilala was Lured by powerful nuclear energy to the Mt. Fuji spaceport, but was covered in a special element which was synthesized to limit his energy intake, Guilalium. Blocked from the energy all around, Guilala became a spore again, and was sent on a rocket to orbit the sun forever.
Eventually, another UFO crashed to Earth, bringing a second Guilala to the planet during the time of a G8 Summit. Realizing the danger of the creature, the president of the United States of America convinces the other world leaders to personally fight back against Guilala instead of fleeing, and each country decides to use their own secret weaponry against the beast. A North Korean general plans to destroy the Guilala with a nuclear missile, but he is warned that if he did so, he will spawn hundreds, even thousands of Guilalas, and backs down. The monster is unopposed until two Japanese journalists discover the legend of Take-Majin, a god who will fight for the humans to defend Earth. Take-Majin and Guilala fight, with Take-Majin eventually defeating the alien creature.
- Guilala can run at over 80 miles per hour.
- Guilala can absorb a variety of different forms of energy, which help him power his attacks.
- Guilala can reduce himself into a spore to allow himself to be undetected. However, this can be turned against him. If enough Guilalium is placed around him, his energy absorption ability is blocked, reverting him back into a spore.
- Guilala can spit fireballs from his beak.
- Guilala can turn into an orb of energy which is capable of destroying everything around it. Using this ability, Guilala can also traverse great distances with extreme speed.
- Guilala can shrug off most blows to his thick hide with little injury.
- Main article: Guilala/Gallery.
- In The Monster X Strikes Back: Attack the G8 Summit, visible tears can be seen in Guilala's neck. This is either to allow Take-Majin's suit actor to cut the suit's head off, or damage caused by repeated attempts at filming that scene.
- Multiple tiny Guilalas and a large Guilala were featured in a commercial for the job search website, The Ladders.