I may not be a professor, but I really wanted to provide my input on this topic. I really like the idea, because it adds more small detail to the game, which is always a useful implementation to make people more interested, but I feel that overall, it is an unnecessary change that really doesn't affect the game whatsoever. Usually, fishing occurs in areas where your health regenerates. Having the sentinel fish cause damage to your wizard would seemingly be a useless addition to the game, considering the fact that your health would most likely refill right after. It is a very interesting idea that could be considered, but I don't think it would be a very useful change that would affect the game overall.