UPDATE: Panda Paws Rescue shared an update on the search for Duncan, the two-legged boxer in Idaho: "A good Samaritan just called and said they saw about an hour ago in a dirt & rock quarry about 2 miles from where the accident was last night. We're at the rock quarry he's here with us and we're trying to find it right now. But there's no sign of him and this place is so vast that huge and dry."

This is a breaking news update. The following is the previously published story.

A famous two-legged dog whose story went viral a few years ago is missing after a crash in Idaho.

"Duncan Lou Who," a two-legged boxer who walked on his two front legs, shot to fame when he used his lime green wheelchair. Duncan's brother Ducky would hop on the back of the wheelchair and the two would take off on adventures together. His story went viral online.

Duncan and his family were driving in Idaho when their car struck a buffalo and rolled over 3-5 times. Two of the family members were treated for minor injuries. Two of their three dogs were ejected from the car through a window. All of the dogs were found, except Duncan.

"I'm in shock. I don't know how my family is alive right now. But our dog is missing after we hit a bison and rolled the excursion 3-5 times (I lost count at 3 & got knocked out). I remember the entire accident. It was horrific & I never, ever would wish this nightmare on anyone. And right now, all I care about is finding our dog, Duncan," said Amand Giese, Duncan's owner, in a Facebook post.

"He DOES walk/run on two legs & we're hoping that when he was thrown from the vehicle that he got scared & ran somewhere to hide. He's VERY friendly. We are still currently searching for him & will continue," said Geise.

The accident happened at mile marker 403 on Highway 87 and U.S. 20 between Island Park and West Yellowstone. Around 20 people, including local EMTs, are helping search for Duncan, but so far he hasn't been found.

"PLEASE, please share this & help us find our boy. Our hearts are shattered right now & I don't have the words to describe how terrified we are at the thought of losing him."