Animals:
* Eel: A school of eels
* Elephant: A herd of elephants
* Emu: A mob of emus
People:
* Ensemble: A company of actors in a play
* Employees: A staff of employees
* Executives: A board of executives
* Explorers: An expedition of explorers
Other:
* Equipment: A suite of equipment
* Eggs: A clutch of eggs
* Eyes: A pair of eyes
Keep in mind that collective nouns can be somewhat flexible, and the specific noun used can depend on the context. For example, you could also refer to a group of explorers or a team of employees.