This has nothing to do with ponies.
The first RPG campaign of the HICU-RPG group was the titular HICU, an acronym for "Human-Involved Crimes Unit." This campaign took place in a near-future universe where all mammals were sentient, though in many cases they could not speak to each other directly due to physical differences. (E.g. mice had to have electronic amplification and pitch-shifting equipment to make themselves heard to humans, and the police had translators carrying this equipment around in backpacks.) Humans remained the hegemonic species of the planet, and the game took place at a time of increasing human-rodent tensions. Space exploration was more advanced in the HICU-RPG universe, with a Martian colony existing in the year 2014 in which the game was set (a year which was in the future at the time the campaign was actually played.)
Synopsis
Los Angeles Police Department members T. Forcym, a career detective rat, Atal, a carnivorous grasshopper mouse on loan from the military, Alex, a computer expert, and Reese, a flying squirrel ornithopter pilot are part of the Human Involved Crimes Unit. They are assigned to investigate a case where a vulcanologist was apparently murdered by a squad of mice with (what were to them) heavy weapons. They uncovered a vast conspiracy involving neo-Zoroastrian cultists, the world's largest non-human-owned corporation and its owner, and a plot to bring the humans to heel before a Mars-based rodent civilization.
Finding that the conspiracy's super-weapon had fallen into the paws of grasshopper mouse supremacists and their violent syncretic religious movement in a compound in Guatemala, the HICU decided that it would be very bad if humans found out how close rodents were to having this power, and teamed up with rogue rodent elements in the FBI to launch a daring extralegal commando raid. Plans quickly fell apart on contact with the enemy, as they do, but the party stole a human-scale excavator and used it to go on massive rampage through the enemy compound, before it fell into a valve pit inside the building where the superweapon was stored.
In the end, the cultists were thwarted, though the party inadvertently caused a nuclear accident that attracted sufficient human attention to result in the whole conspiracy being exposed. The party escaped Guatemala and successfully hid out in the South Pacific.