Given the question: What's the surname of the person who tries to drown someone?  Answer the above question based on the context below:  Long ago, a young Plains warrior is tested by being the target of three different weapons.  Centuries later, Ernest P. Worrell works as a maintenance man at Kamp Kikakee but hopes to become a counselor. He quickly becomes a valuable addition to the staff, skilled at Plains Indian Sign Language, used by Kikakee's owner, Chief St. Cloud.  A small group of juvenile delinquents, the Second Chancers, come to Kikakee. Head Counselor Tipton assigns Kikakee's most experienced counselor, Ross Stennis, to be the boys' counselor. Stennis is unhappy with this assignment, and he treats the boys harshly. After he goes too far by intentionally causing Moustafa Jones, the smallest boy in the group, to nearly drown in the lake during swimming, only for Moustafa to be rescued by Ernest, the boys retaliate against Stennis's cruelty by toppling his lifeguard perch into the lake, badly injuring Stennis's leg in the process. Since Stennis is no longer able to perform his duties as a counselor and Kikakee is already shorthanded, Tipton offers Stennis's position to Ernest. The Second Chancers initially give Ernest trouble, but they start to show respect during a campfire session when Nurse St. Cloud translates her grandfather's description of the warrior initiation ritual for his tribe. The initiate must hold still while a knife, a stone hatchet, and an arrow are thrown or shot at him. The courage of the young warrior apparently alters the course of each weapon to prevent it from striking him. The Second Chancers build a tepee only to find it burned. They fight Pennington, one of the regular campers, because he was responsible. Tipton is poised to expel them, but Ernest convinces him otherwise.
The answer is:
Stennis