"One taxi- BEEP BEEP I'M A SHEEP!"
Sheep Taxi is actually a true Gregory meme using Sleepy Sheep and The Taxi (figure out it's real name on the wiki plz) combined with ASDF.
His attacks is a reference to ASDF.
He looks like The Taxi, but instead of "Do you remember me?", it is instead "Do you MEOW YOUR COW?" and with Sleepy Sheep in the Taxi.
I like Horses.
This is the attack he commonly uses. Apparently when he uses this attack, he summons a train full of horses.
Here's YOUR Cow!
Basically, he appears big on the screen, holding a cow about to throw it, when it gets closer it turns out it won't change it's size. Somehow.