Is Templeton from Charlotte's Web good or bad in chapter 21

Templeton is not good.

Explanation:

Templeton is a selfish and self-centered rodent. He does not want to save Wilbur's Life and it takes a LOT of coaxing and bribery for him to help save Charlotte's egg sac.

Here is the Author's description of their least favorite rodent:

"The rat had no morals, no conscience, no scruples, no consideration, no decency, no milk of rodent kindness, no compunctions, no higher feeling, no friendliness, no anything."

appeal to ethos is your answer.

the answer is industry