Hero is a female sockeye salmon named by Martin Kratt because she saved his life twice. She made her first appearance in the first part of the special Wild Kratts Alaska: Hero's Journey and died in the special's second part.
Martin promised to help her get home on the salmon run with help from Chris Kratt. In the end she finally made it to the exact place where she was born to lay her eggs, but died soon afterwards. However, her eggs, the next generation of salmon, were safe in the river. Martin named a hatching after her, Hero Jr..