Basic Trope: A character has a friend for one episode who never shows up again.
- Straight: One episode of The Spencer Show revolves around Spencer playing sports with his friend, Evan. The audience has never seen Evan before or after this episode, and he doesn't appear again.
- Exaggerated: The entire episode, Spencer acts like he's known Evan his whole life and they're the best of friends. Later episodes have him with totally different friends and Evan never appears again.
- Downplayed: Spencer calls his acquaintance Evan, who helps him out for a day, but then goes back to his regular life.
- Justified:
- Evan lives very far away, so Spencer doesn't get to hang out with him very often. He just happened to be in town that day.
- Something happened that broke Spencer and Evan's friendship after the episode.
- For the most part, Evan isn't interested in most of Spencer's activities. But for the one time Spencer cares about sports, Evan is there to help him.
- Spencer is Evan's Make-A-Wish friend. If nothing else, Spencer made his last few days happy.
- Inverted:
- Spencer acts as though he's had a lifelong rivalry with Evan, even though he never appears again.
- Spencer always treats his established friends like he's meeting them for the first time.
- Subverted: Evan gets written out at the end of the episode, so viewers don't expect him to show up again. But he does come back later on.
- Double Subverted: Except when Evan returns, Spencer doesn't seem to recognize him as a friend.
- Parodied: The entire episode is dedicated to showing off Spencer and Evan's friendship, down to retconning Evan into past scenes that he wasn't even there for.
- Averted:
- Spencer's social circle is kept consistent, with no additions or removals.
- Spencer meets Evan, and Evan sticks around.
- Evan has been a friend of Spencer since the start of the show.
- Enforced: The writers realized that none of the characters they currently have would fit the "Spencer playing sports" storyline they want to do. So they add in a new character to guide him, just saying that they're already friends.
- Lampshaded: Spencer's friend asks, "Since when have you had a friend named Evan?"
- Invoked: Whatever the case, Evan decides he doesn't want to be in Spencer's life anymore after the episode, and takes his leave.
- Exploited: Since Evan knows that all his friendships are temporary, he tries to take advantage of his "friends" while they last.
- Defied: Spencer and Evan make sure to stay in contact with each other.
- Discussed: A conversation between two of Spencer's friends:Mary: So, Spencer's friend Evan, have you met him?
Bart: No, have you?
Mary: I hadn't even heard of him. - Conversed: "Wait, who's Evan? I've never seen this character before."
- Played for Laughs: Everyone is confused by Evan's sudden appearance, and Spencer has to repeatedly explain who he is.
- Played for Drama: Evan isn't mentioned again because he was murdered, and the experience is too painful for Spencer to want to remember it.
- Played for Horror: Evan is a Serial Killer who "befriends" his victims, then kills them.
Say hi to your Single Serving Friend, but don't expect him to stick around.
