Igneel

Igneel is a dragon and the foster father of Natsu Dragonil. He taught Natsu how to write, speak, and even how to use the fire-brand style of magic known as "Dragon Slayer". For some still unknown reason, Igneel disappeared one day without saying a word to Natsu, leaving Natsu to fend for himself. Natsu dreams of meeting Igneel again, and searches for clues of his whereabouts throughout the series.

Tower of Paradise Arc
After the events at the Tower of Paradise, Igneel is shown residing in a volcanic region, talking to someone name Grandmine about Natsu. Igneel then ordered Grandmine to leave once it sounded like he threatened Natsu. He made reference to Dark Mage Zeref and the dragons' removal from human affairs.