Ethan

Ethan is an teenage boy who lives with his two parents and Larry the Dog.

Pre-Infection
Before the outbreak, Danny lived with his parents and presumably went to elementary school. It is implied that he had a particularly negative relationship with his father.

Post-Infection
The night of the outbreak, Ethan decided to stay up late and watch TV so he could memorize crass jokes to repeat at school. His dog stayed up with him. An intruder broke into Ethan's house and tried to inject him with an unidentified substance (containing the virus). Larry protected Ethan but was injected instead. The intruder fled, and Larry grew to twice his size and ripped Ethan's throat out before escaping as well. Ethan's parents tried to come to his aid, but he died very quickly.

Killed By
The intruder infected Larry, causing the dog to kill Ethan.
 * Larry the Dog
 * Intruder (caused)

Trivia

 * Ethan is the first character to die