Snippet from wiki (IEntityDefinition) :
//returns "net.minecraft.entity.passive.EntitySheep"
<entity:minecraft:sheep>.id;
Relevant called code (according to IEntityDefinition and MCEntityDefinition, in order) :
@ZenGetter("id")
String getId();
@Override
public String getId() {
return entityEntry.getRegistryName() != null ? entityEntry.getRegistryName().toString() : "no_registry_name";
}
The registryName for EntitySheep is minecraft:sheep, as you can see in EntityList.init() (id 91)
The comment should therefore be edited to //returns "minecraft:sheep"