

The proffesor is a stallion who appears in "The Crystal Empire: Part 1" (season 3) during th Failure Success song. When Twilight recites the square route of 546, he is seen writing her answer out on the chalk board and confirming that it's correct.
He is seen wearing a white collar with a black tie around his neck, a sweater over the top and large, black rimmed glasses.
His cutie mark is a molecule