Gabo

First introduced in PoPoLoCrois MonoGatari II (Book 3 in the PSP version), Gabo was first shown when Pietro and the White Knight kill the Earth Dragon. As a result of the white knight being the first living thing that Gabo laid eyes on, Gabo now see's him as his father, and thus follows his every move, and at times even tries to imitate him (one of Gabos attacks has him wearing a blue cape and attacking in the exact same fashion as the White Knight). His character is often underestimated thanks to his extremely low health points and lack of physical attacks, but if the player devotes enough time to hunting down certain monsters scattered throughout the land, Gabo can learn special summons involving these monsters that are quite useful. Gabo is unaware that Pietro, and his "father" White Knight, killed his mother. Pietro did not do this act intentionally, but was set up by Maira. 

The locations of Gabos 6 Summons are as follows:

His location is in the Bryonia Library, accesible from Pashtov's Pasela Boat Tour. He is capable of using a magic water attack that hits all enemies. MP cost of 60.

His location is Uranos Square next to Takinen Village. Continue straight into the woods, and you will stumble upon him. He is capable of a using a wind attack that hits all enemies. MP cost of 70

His location is in the fairy forrest, next to Leona's house in the woods. He does a standard melee attack that hits all enemies. MP cost of 60

His location is on the second floor of Roma Castle, within a unicorn painting. He is capable of using a heal / remove all negative status abnormalities on the entire party. MP cost of 60

His location is in Castle PoPoLoCrois basement, within the Dragon Painting. He does a regular melee attack of very high damage to all enemies. MP cost of 90

Located on the Remoira Continent, located within a tapestry of a knight in the starting room. By far the most difficult of all summons to acquire. White Knight seems to know King Knight somehow...