Which enemies carry explosives that can be blown up with Fuse?

Avent Troopers and Officers, both Advent Mec, Mutons, and Andromedon

Also you can fuse nades on dead bodies

[Edit]

The wiki indicates that Troopers and Mutons always have nades http://xcom.wikia.com/wiki/ADVENT_Trooper

http://xcom.wikia.com/wiki/Muton_(XCOM_2)