There have been some jaw-dropping profits made throughout Dragons’ Den’s history (Picture: BBC)It’s been on our screens for nearly 20 years, but Dragons’ Den continues to find amazing success stories. Who are the dragons on Dragons’ Den? As we all know, not every success story from Dragons’ Den actually secured an investment. The seven biggest Dragon’s Den success stories that got rejected on the showHis product, called Pippa, is a stove alarm that monitors cooking hazards and uses an intelligent temperature sensor and AI-powered thermal imaging. Dragons’ Den returns on BBC One at 8pm tonight.