Miles "Tails" Prower

Miles Prower, better known by his nickname, Tails, is a young monster who stops at nothing to see his idol, Amy Rose, in action.

Appearance
Tails is a yellow, vulpine monster with two tails, and a tuft of fur on the top of his head. Having two tails and frequently running everywhere, he trips and fall often. He has black markings on his eyelids. He wears a yellow shirt with brown stripes.

Personality
Tails looks up to Amy as a role model. He is an innocent monster who assumes an energetic attitude that pervades most of his actions. He seems to be a bit naive, as well as a bit clumsy, as he trips frequently. He also uses words like "c'mon," "dude," and "yo" frequently, usually considered childlike ways of interaction.

Despite the protagonist notably frightening Tails during the Genocide Route (once he discovers the protagonist's intentions), he stands up to the protagonist with an intense expression, ready to protect the Underground, trying to act like Amy. Choosing to spare him aborts the Genocide Route and reverts him back to a more favorable opinion of the protagonist, showing a rather forgiving nature.

Neutral Route
Tails first meets the protagonist in Snowdin. He notes how both of them are wearing striped shirts, so they both must be children. However, he do not seem to notice that the protagonist is a human child.

He later sneaks out of Snowdin to explore Waterfall, looking for Amy. He follows the protagonist, not knowing that the latter is a human whom Amy is searching for, and he feels a little jealous of the attention that the protagonist receives.

While walking across a bridge, Tails finds out that the protagonist is a human and reluctantly considers the protagonist an enemy. He tries to say something mean to the human, in an attempt to become enemies, but feel bad for it and start to leave.

Just as Tails leaves, he trips over the edge of the bridge and hang from it (presumably with his teeth) as Amy approaches. The protagonist must make a choice:
 * Help him climb back up: Tails defends the protagonist from Amy, who backs off. He decides to remain friends with the protagonist and leave for home.
 * Let him fall: Amy dives down after Tails to save him. She is badly hurt but refuses to rest. He then tells Amy that she was right about the human, who just stood there waiting for him to fall. This response makes Tails hate the protagonist and all humans.
 * Run to Amy: Amy saves Tails and is badly hurt. He tells Amy that she was right about the human, who was too eager to fight her to bother saving him. This response also makes Tails hate the protagonist and all humans.
 * Run away from Amy: Amy helps Tails up, who tells her that the protagonist was just going to get help from others.

True Pacifist Route
Tails is seen cheering the protagonist on to victory in the bottom-right corner of the battle screen as he faces off against Leslie. In the epilogue, he can be found in Snowdin. If saved earlier, he says he does not think Amy is that great anymore, and that he found himself a new idol, likely Sonic the Hedgehog. He is also seen during the credits, attending Fluttershy's school.

Genocide Route
Despite being warned by Amy that the protagonist has hurt a lot of people, Tails approaches the protagonist in disbelief. The protagonist turns away, and as Tails questions the protagonist about not answering him, the protagonist silently approaches him with a "weird expression," causing him to step back. Tails begins to panic and wonders what he should do, and then stands up to the protagonist out of desperation, trying to act like Amy, stating nervously that if the protagonist wants to continue to hurt others, the protagonist would have to go through him. The protagonist then proactively engages battle with him, with the narration simply declaring "In my way." If the protagonist dies, reloads at the unnamed save before the bridge and returns to this location without the viewer closing the movie, he simply attempts to trick the child into turning the other way before re-engaging. This encounter cannot be escaped. A slowed down version of "Anticipation" plays during the battle. If the viewer resets after this scene (most likely by dying to Amy), the scene is abbreviated: after Tails approaches the protagonist, the protagonist tricks him into turning the other way, then re-engages battle.
 * If the protagonist attacks Tails, Amy takes the fatal blow in his place. The fox escapes while harboring a shocked expression, and the protagonist fights Amy Rose the Hornhog. Tails is not seen again for the rest of the movie; it is assumed he evacuated with the others.
 * If the protagonist spares Tails, he says he knew the protagonist was not that bad and leave. This action aborts the Genocide Route, and the protagonist fights Amy later in Waterfall normally.

Trivia

 * Tails is the fourth fox character to bark in certain circumstances. The first three were Nick Wilde, Finnick, and Baby Nick.
 * Tails is also the second male character to be voiced by a female. The first was Charmy Bee.