Green’s Dictionary of Slang

(US campus) a toady, a sycophant.

1804		Monthly Anthology I 153: You besought me to respect my teachers, and to be attentive to my studies, though it shall procure me the odious title of a ‘fisher’ [DARE].
1856		B.H. Hall College Words (rev. edn) 200: fish, fisher. One who attempts to ingratiate himself with his instructor, thereby to obtain favor or advantage.