Mordor Trebuchet is pretty funky, simulating chucking a rock at your foe by giving you a flying "ballistic boulder" token to aid in your attack. Of course, we all know that what goes up must come down, so the rock comes tumbling down at the end of combat, its service done. Oh well, it was nice while it lasted.
But what if it didn't? What if, like all good triggered abilities, you simply swept it away and kept your boulder... forever? That classic rules-twister Sundial of the Infinite comes to the rescue here, throwing away that unseemly end-of-combat trigger by ending your turn as soon as you're done attacking. In exchange, though, your flying projectile sticks around! Once it's staying for good, it becomes self-aware and can do anything any other flying creature can do: attack, block, pick up equipment, you name it. The payoff here may not be quite as impressive as the rude tricks you can pull via Phyrexian Dreadnought or Final Fortune, but isn't cultivating a growing herd of flying rocks way funnier?
Changeling Outcast, Prickly Boggart and Squeaking Pie Sneak are all cheap and evasive goblins in black, letting you get those boulders rolling with little risk of your gobbos being blocked and killed. Cranial Plating is a nasty force-multiplier, gaining a bonus from your Sundial and various boulders lying around (flying around?) to be stuck onto an evasive attacker - including a boulder, since it can be equipped mid-combat! Dollhouse of Horrors may not particularly synergize with your modus operandi, but the construct tokens you bring back get boosted by all your boulders - when that's attached to an evasive body, the damage can pile up quick!
Just don't ask how a sundial still works once you have enough Ballistic Boulders to block out the sun!