These cyclists definitely picked up the pace when they realized who was tailing them.
As a video by Viral Hog shows, a huge ostrich chased a group of bikers as they prepared for a race in South Africa on Friday.
As Oleksiy Mishchenko, from Switzerland, posted the video to YouTube on Saturday, he said the road to the "Cape of Good Hope" had been "quiet and a little deserted" until they were joined by their feathered friend.
"Suddenly, I spotted a white ostrich on my left, then this beast jumped on the road from the right and started chasing my friends!" he recounted. "It was a little scary at first, but then I thought I gonna fell of my bike from laughter."
He added: "The ostrich didn't have any problem to keep up at 50km/h [31mph] and apparently they do 70km/h [43mph] with no sweat."
While the bird looks like it's catching up with them, it eventually gave up - which was for the best.
"Luckily the creature decided to leave us alone, as we were running out of road," Mishchenko said. "The Cape of Good hope is a dead end way."
The video has since been viewed more than 700,000 times.