Cobb, Frog? Wizard

'Cobb was once a decently successful luxury goods trader in Ank'Jir. When he realised that he had an aptitude for magic, he put his business in the care of a trusted steward and enrolled in the mage academy there. While he was a gifted and hard-working student, a momentary mistake born from overeagerness to learn caused a magical explosion that both wiped out some very expensive materials that belonged to the academy and polymorphed Cobb into a frog. The professors were unable to turn him back into a human and he couldn't continue his studies as he was, so he set out to search for a renowned cleric whom he hoped could cure his condition.'