https://www.democraticunderground.com/100220007444

The tale of Caligulas horse, Incitatus, being appointed as a senator is one of the most outlandish anecdotes about the emperors supposed madness. Incitatus was not just any horse; by all accounts, Caligula lavished him with luxuries typically reserved for Romes elite. The horse lived in a marble stable, with an ivory manger, and was the recipient of jewelry and other decadent trappings of wealth. The story goes that Caligula was so enamored with Incitatus that he intended to make a farce of the senatorial proceedings by raising his horse to the high office of a consul.
https://historychronicles.org/caligula-a-mad-tyrant/

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Updated to include Orange Caligula ordering his soldiers to whip the sea.
Whip it good.
https://www.democraticunderground.com/100221167895
Caligula - the Mad Emperor who Declared War on the Sea

According to Suetonius and Dio, he summoned his legions to the shore, arranged them in battle formation, and ordered them to prepare for an assault on the sea.
Trumpets sounded, arms were raised, and the soldiers awaited further instructions as if facing a real enemy.
Then, with no warning, Caligula dismissed the battle and declared victory. Ancient authors later interpreted this as a symbolic triumph over the god Neptune. Next, he instructed the troops to collect seashells along the beach and store them as trophies of the campaign.
According to these accounts, the shells were boxed and carried back to Rome as spoils of the conquest.
source: https://www.historyskills.com/classroom/ancient-history/caligula-attacks-the-sea/