It is possible to make custom ones if you are willing to make a few sacrifices.
You create a workshop that will be your fake siege weapon, and a reaction to fire that siege weapon. Then you got two choices: dfhack or evaporating stones. Evaporating stones are easier, but are less reliable. Either the stone or the script will apply a syndrome that can either be:
a) transform into a creature that cannot move, but can use a material emission interaction, or b) lower the speed of the creature into nothing and give them a temporary material emission interaction.
That's as close as you can get.
That gives me an idea. Now, is this just me being crazy, or would it be possible to make functional trebuchets like that? Trebuchets that attackers could bring when besieging your fort?
I'm thinking, essentially, a slow moving wooden creature with no attack, that has an interaction that it would do upon seeing an enemy, where it would turn into an immobile creature with a slow, long-range, devastatingly powerful material emission interaction that essentially hurls large stones. It would have another interaction it uses when not in combat to turn back. Both interactions would have a very long wait time.
But would it be possible to make an interaction that a creature uses on itself upon seeing a hostile? Perhaps give the creature [FLEEQUICK] and have the usage hint set to fleeing?
And is it possible to make an interaction that can destroy walls?