Completely disappeared without a trace. And deserters, who should have been brought back from previous installments of Heroes.

Alex Ghost, that's a cool idea about the animal symbols! I just wouldn't make them creatures that participate in battles, but rather keep them near the hero! Meaning, the animal symbol gives some kind of bonus!

Basically, I came up with this after playing Dark Messiah – in that game, spiders were highly revered by the necromancers because the spider was a symbol of the Dragon of Order, Ash, a goddess revered by necromancers... The necromancers saw Ash as embodied in the spider, and throughout the game, we are periodically treated to horror scenes with spiders in the main role... Nevertheless, it's quite normal that there were spiders, because necromancers are a very mystical and frightening race... We're not scared by things like "Resident Evil" anymore, but honest medieval people would drop dead from a heart attack just from seeing the undead... The spiders turned out well – as an absolutely necessary part of the game's gameplay...

And since necromancers revere spiders, why shouldn't other races have an animal that is a symbol of the race – let these creatures be not only a neutral unit in the army, but also a part of the race (meaning, like a division of neutrals in the fourth game), giving some, even if small, bonus in the "native" armies...

For each race, there will be its own animal symbol... For necromancers – spiders, for dwarves – bears, for Dark Elves – snakes (cobras or other representatives), for Orcs – wolves, for Elves – white tigers (a tentative option), for humans – lions (also a tentative option), etc... And let these animals be full-fledged units...
And let the rest of the animals be free, but pathologically appropriate for certain types of terrain... Later, I think they can also be linked to "new" races, such as the swamp race being developed...