Heroic monsters are a special type of monster on the Kingdom map.
It is almost impossible to defeat heroic squads alone. To succeed, you will need all of your army's strength as well as your Clanmates’ help — you can use reinforcements in these battles.
The reward will be just as significant: all members of your Clan will receive a special chest containing well-deserved rewards, as well as Valor and Experience points, unique items (more about them here), and Clan resources: Scientific Tractates and building resources.
Clan chests that are granted as a reward for defeating a heroic monster squad will be credited to all march participants as soon as the group march has been disbanded and all reinforcements have returned to their respective Cities.