Nicodemus

Nicodemus is a major character in The Secret of NIMH. He was the leader of the rats who escaped from NIMH.The rats of NIMH were experimented on until they eventually developed human level intellect. Nicodemus became the most intellectually gifted among his kind so when the rats escaped their cages Nicodemus was made their leader.

Nicodemus gives Mrs. Brisby a mystical charm of his and offers to save her family to repay the kindness of her husband, Johnathan Brisby, who was instrumental in helping the rats escape NIMH. By the end of the film Nicodemus dies in his attempt to save the Brisby family.