Who is Pepper in The House on the Borderland?

Pepper is the loyal dog and companion of the old man who narrates the manuscript found in 'The House on the Borderland'^[1]. The narrator considers Pepper his only friend, preferring him over 'the rest of Creation together' because he understands him and leaves him alone during his 'dark moods'^[1].

Pepper is depicted as brave, though he whimpers and cringes during the strange, ghastly green and ruddy light phenomena in the study^[1][1]. He plays a crucial role in several encounters with the 'Swinethings,' creatures that emerge from a deep ravine known as the 'Pit'^[1]. Pepper is wounded by one of these creatures, sustaining a 'great claw wound in the side that had almost laid bare his ribs'^[1].

Despite his injury, Pepper later follows the narrator into a subterranean passage connected to the Pit, where he saves the narrator from being swept into a bottomless chasm by a torrent of water^[1][1].

As the narrator experiences an extreme acceleration of time, witnessing days and nights pass in seconds, Pepper, who had been sleeping, 'fell to pieces'^[1], crumbling into 'a mouldering heap of bones and dust'^[1]. This indicates that Pepper had reached 'the time of his dying' due to the 'sheer length of years' that passed during the accelerated time^[1]. The narrator keeps the 'little heap of grey ash' on his study floor as a tangible reminder of Pepper^[1].