Cohen admitted that the Jason Bradbury-fronted teatime series "didn't work", but claimed that it was right for the broadcaster to take risks on "creative and innovative ideas".
"Some [shows] will work and some won't. You have to be prepared to fail," he said at the Edinburgh TV Festival.
"It didn't quite catch on. People didn't engage with the robot in the way we hoped."
Cohen added that he was on the lookout for new formats to fill the "Total Wipeout teatime slot", which he described as one of the trickiest to schedule.
Don't Scare The Hare dipped to 1.3m in overnight ratings during its run in the spring.
> BBC One's Danny Cohen: Meet The Controller - Live Blog