The teen then tried to convince him to eat his own mother.
"The victim's 13-year-old son blamed his thought process on his drug usage and said he would never do anything like that sober," according to a statement from the Spokane County sheriff's department.
The teens have been charged with assault, burglary and other crimes.
Meanwhile, the mother was hospitalized and was in stable condition by Wednesday. The mother's name has not been released.
Sheriff's deputies arrived to a call of an assault and found a woman in her bed, bloody, with two knives and a sword with a bent handle near her.
Because they found no signs of forced entry, deputies began to suspect the woman's 13-year-old son and his 14-year-old friend.
When they went to the home of the friend, the father reported that his Dodge Durango SUV and keys were missing, which matched an earlier hit-and-run report. They found the Durango running with the keys still in the ignition, crashed into a mobile home.
The department's canine unit helped find the teens, who had been hiding nearby.