Simple arrival phrases travel well because they’re instant. “Is here” compresses time: it implies the next step is now. That compression is great for attention—especially in short-form platforms where viewers skim for cues.
It also creates a built-in escalation. Even if the horse is imaginary, the phrasing tells you something is approaching the moment of attention. That makes the line useful for comedy (overreaction to something small), suspense (something unexpected is coming), or hype (“the moment has arrived”).
In many viral formats, the power isn’t the literal claim. It’s the performance. The speaker’s tone—captioned, shouted, or timed to a clip—turns “peter the horse is here” into an event, not a sentence.