It must be mentioned that Sassy Saddles was not a mare of little brain. Nor was she wicked of heart, malicious of mind, or in any way morally deficient by the standards most ponies hold. She was merely sassy, and the old hobo's attempt to dictate her behavior, however well-intentioned, had offended certain deep-rooted sensibilities she held in regards to her own autonomy. So it was that she found herself trotting along the railroad tracks towards Ponyville, fuming at the memory of the hobo's melodramatic warning.
"Nopony's going to tell me what to do," she said. "Well, not without paying me, anyway, which would clearly fall under the purview of contractual obligation. That's an entirely different matter. Nopony's ever going to find my signature on any contract written up by a filthy old hobo with a..."
Her monologue ground to a halt as she caught a brief glimpse of something in the woods nearby. She saw it for only a moment, but it was tall and ape-like in form. It strode by, stopping for just a moment to glance back over its shoulder at the unicorn, who responded according to her custom.
"A filthy old hobo with a penchant for spreading ridiculous urban legends about imaginary creatures that could not even be supported by the local ecology!" she nearly shouted, staring at the copse of trees into which the thing that most certainly could not have been a sasquatch had just disappeared.
"Bodices and bullhockey," she grumbled to herself, continuing to trot forward. "If that idiotic creature thinks I'm going to believe in it merely because I've seen it, it is mistaken."
She continued forward, fully aware that she had seen the sasquatch, yet still choosing not to believe in its existence. It was perhaps rather arbitrary of her, and in point of fact did call into question the precise parameters defining the concept of belief. To Sassy, however, these concerns were tertiary at best. In effect, failure to maintain her state of skepticism would be tantamount to a failure of sass. There were few things in the world that Sassy Saddles could not endure, but to know that she had allowed even a momentary lapse of sass was indubitably one of them.
Sass was the essence of her being.
Not ten minutes later, she saw the creature again. This time, it stepped from the woods some thirty yards ahead of her. She did not stop moving along the tracks, however. To do so would, in some capacity, have meant acknowledging the creature as real, and Sassy Saddles would have none of that.
As she drew closer, she got a clear look at it; perhaps the first such look of anypony, ever. Cryptozoologists the world over spent lifetimes waiting for moments like these. They endured accusations of quackery and fraud in search of financiers with the whimsy -- nay, the hope -- left in their hearts to give them research grants. They crawled through mud, risking disease and courting failure, all for the dream of one brief glimpse of such a creature as this.
Sassy Saddles passed it by with no more than a sidelong glance.
It was a hideous thing, overdeveloped in its musculature, with bulbous forearms, flabby lips, small eyes, and a vacuous expression on its round face. It stood scratching its posterior with one hand, and gnawing on a tree branch clutched in its left. It turned its head to watch as Sassy Saddles passed it by.
"Eating wood, eh?" she said. "A gallant effort at disproving my statement in regards to your unsuitability for the local ecology, but all you've done now is imply that you are most likely a mutant beaver."
The creature bit off a chunk of the tree branch, gave it several solid chews, and swallowed it, producing an audible gulp.
"UWAH!" it yelped.
"'Uwah,' indeed," said Sassy. "As if any real undiscovered marvel of nature would have a cry so boorishly inelegant."
She continued on her way, ignoring the would-be sasquatch, which for the moment seemed content to finish eating its tree branch.
"When I tell her this story," said Sassy, continuing forward, "Rarity is going to have quite a laugh about how thoroughly I did not believe in that sasquatch."
It was no more than a mile further before she reached her next obstacle: a rail bridge over a wide river. There, right at its center, as if awaiting her arrival, was the thing that according to no natural law could ever in all the realm of possibility occupy a state of being equating to sasquatchhood.
"Because sasquatches do not exist," said Sassy Saddles, having just had this precise thought.
The not-squatch waved at her from where it stood on the bridge.
"UWAH!" it cried.
"Myths and mittens," she grumbled.
"Uwah?" blurted the thing.
"I am crossing the bridge," said Sassy Saddles, "which I would most certainly not do if there was a sasquatch standing on it."
She walked forward, continuing to speak.
"Ergo," she said, "you cannot be a sasquatch, for if you were, I would not be doing what I am doing."
"Uh.... Wah?" said the creature as Sassy drew nearer.
Had she not been so deeply invested in enforcing her own disbelief, she might have noticed that the beast held out towards her as she passed a large, round rock which had been emblazoned with a crude smiley face, painted thereupon with some substance best left unidentified. Now, what the weird ape-beaver believed the significance of this rock to be is impossible to discern. Perhaps it was some sort of offering; a token of a desire for friendship. Perhaps the creature had been smitten with Sassy, and it was a gift given in deep, heartfelt affection. Perhaps it was something the beast found behind the Ponyville schoolhouse while raiding the trashcans, and it was trying to play a game of show-and-tell.
Whatever the case, Sassy's decision to ignore the proffered stone was met with a crestfallen expression and a meek, quiet "Uwah."
At this, having already made it several paces beyond the thing that was not a sasquatch, Sassy stopped, and spoke over her shoulder.
"Don't pout," she said. "Matters could be worse. After all, you could be a sasquatch."
The apish thing seemed to think this over for several seconds, its head tilting ever more slightly to the left as it did so. It blinked several times, grunted and groaned under its breath, and finally gave a slight shrug. With a resolute, affirmative "Uwah," it tossed the rock into the river. The rock was several times larger than most ponies' heads, and it produced a splash well in accordance with its mass. Much to her dismay, several droplets landed on Sassy's dress.
"Desecrating Deluges!" she exclaimed, turning to face the giant, hairy ape that, despite constituting a more than adequate match to all extant descriptions of one, was still, beyond a shadow of a doubt, not a sasquatch. "This is suede trim! Do you have any idea what you could have..."
She was halted by a peculiar sound. It was most readily likened to a cement mixer full of goats, and it was coming from the not-squatch. The thing was giggling, she realized, and also clapping its massive, oar-like hands.
"What are you laughing at!?" she growled. "Blouses and Buttonholes, I ought to..."
The creature's giggling intesified, and it began to clap more vigorously.
"Wait a moment," said Sassy, her left eyebrow raising slightly. "French cuffs and frock coats."
The goats in the cement mixer brayed more insistently than ever, and the five-fingered paddles slammed together with such force as to produce a noticeable breeze, even from where Sassy was standing, several paces away.
"You like that, don't you?" she said. "I suppose it takes all kinds."
She gave the creature a smile and a nod.
"Nice to have met you, mutant beaver, but I must be on my way."
"Uwah!" barked the mutant beaver.
She turned and walked onward. Before she had made it more than a few paces, however, the creature had stridden up beside her, and was keeping pace, as if it meant to accompany her for the duration of her journey.
"Very well, whatever you are," said Sassy Saddles. "You may walk with me to Ponyville, but I recommend against allowing yourself to be seen there. You might be mistaken for a sasquatch, and that could cause a panic."