Madmole

A Fifth Generation Dragon Slayer and member of Diabolos, a guild of dragon eaters.

Compared to his comrades, Madmole is more mellow and polite, using honorifics such as "-dono" to address others. In contrast to Kiria’s brash attitude, Madmole is practical and prefers to be more strategic when it comes to facing stronger opponents, such as Mercphobia.

At some point in time, Madmole devoured an Armor Dragon, which enabled him to take on their power. He then joined Diabolos, a guild exclusively comprised of Dragon Eaters, fifth generation Dragon Slayers.

(Source: Fairy Tail Wiki)