Battering ram!
It would be made in the siege workshop and would be manned by one recruit (that sometimes eats too

Why is this better than the "old" siege weapons already present in TPR?
Well, for once it wouldn't be able to harm soldiers: it is a unit you specifically make and deploy for buildings.
(Please note that civilian buildings can already be disabled with a single melee unit, which is easier and faster to "infiltrate" in the enemy town...)
Also, it would not be ranged: it would be risky to use it, and must destroy the target tower quickly or be destroyed.
It would eat (like all other units in the game do) and would not move around on its own (even though the recruit may not be visible, since he should be taking cover under the ram's shielding).
The only problem I can see at the moment is that, as far as I know, there aren't sprites for this yet.
The battering ram would add a specific counterplay for towers, and make melee units more important during sieges.
Especially mounted units, as they can get in, destroy the ram, and get out before taking too many ranged shots; as an indirect effect, making cavalry more important would also make anti-horse troops better, simply because there would more often be "horse troops".
Any opinion?