Spekkio refers to himself as the "Master of War". When the party first meets him, he tells them that he has seen many battles from the End of Time. He tells the party that many years before they were born there existed a kingdom where magic was everywhere and where anyone could use it. However, people began to abuse their power over the years. Eventually, it became so bad that only fiends were allowed to use magic. He goes on to say that the party has determination and that magic only needs power of the heart and inner strength. He says that magic is divided into four types: Fire, Water, Lightning and Shadow. He tells them that Crono is adept at Lighting, Marle is adept at Ice, and Lucca is adept at Fire. He then tells them all to think magic and then, starting from the entrance to his room, run clockwise along the walls three times. They do this, and then Spekkio grants them their magic powers.
Later, when Frog comes to see Spekkio, he is granted Water magic. Ayla cannot be taught magic due to her existing before magic was discovered, and Robo cannot be taught magic because he is not a living thing. Magus does not need to be taught magic as he already knows a great deal about Shadow magic as he was originally alive when magic existed.
In the Bend of Time, Spekkio seems to still be around. If Janice is brought to the area, the timekeeper will note that the "God of Combat" has taken an interest in her, and she will be bestowed her level 7 tech, What'sUpDoc. He still has his own separate room, and after a trial similar to the one in Chrono Trigger (involving running three laps around the room) he offers a battle with Ozzie, Slash, and Flea, the Mystical Knights. A minigame ensues in which one must run a correct number of laps to receive a Dreamer's Sarong. After the minigame is won, he remarks that perhaps he will see the player in another, different dimension. This strongly suggests that it is indeed the cheerful creature.
After giving Crono, Marle, and Lucca their magic, he asks them if they would like to battle. Doing so will give them a reward. The reward becomes better the higher the party's level is.
Spekkio is a unique enemy in that his form will change depending on how strong your team is. When a member of the party is between levels 1 to 9, he will be in the form of a Prehistoric Frog (Most players never see this form since most would be past level 9 by the time they meet Spekkio). When a member of the party is between levels 10 to 19, he will be in the form of a Kilwala. When a member of the party is between levels 20 to 29, he will be in the form of an Ogan. When a member of the party is between levels 30 to 39, he will be in the form of a red Gaoler. When a member of the party is between levels 40 to 98 he will be in the form of a blue Masa & Mune. And finally when a member of the party is level 99, he will be in the form of a pink Nu, the hardest enemy in the SNES/PS versions and one of the hardest bosses in the DS version of the game, next to the Dream Devourer.
'Spekkio' is a phonetic spelling of the Italian word 'specchio' (meaning that they are spelled differently, but are pronounced the same). 'Specchio' means 'Mirror' in Italian, which is perfectly descriptive of Spekkio's role in Chrono Trigger. He is a reflection of the party's current power level; a mirror. It is from this that Spekkio got his name.
If Spekkio is found in any of the forms past his first, all previous forms will appear in the Bestiary if they weren't there already, even if they were never fought.