Wander and Sylvia board an abandoned spaceship when Wander thinks someone in there needs help. However, Wander gets distracted by some kind of yellow acid that lands him into trouble. Sylvia, on the other hand, discovers that the spaceship used to belong to a man named Captain Tim and his crew, but are devoured by creatures. Now officially scared, Sylvia rushes to find Wander and is found by a spider-like alien creature. Luckily, she fights it off and gears up to find Wander.
Wander, who is still looking for someone to help, encounters the creature as well and grows a liking to it. After playfully running from it, Sylvia catches the creature again, only this time he catches her and makes her into a cocoon-type of spider web. Luckily, she escapes and gears up even more to save her best friend.
The creature finds Wander, and the nomad soon finds Captain Tim's name tag in his mouth and names the creature after the real captain that had been seen being devoured earlier. Wander puts a leash on "Capt. Tim" and begins trying to train it to be his 'pet'. After feeding him a can of beans, Wander assumes that Capt. Tim needs a nap and pulls out a teddy bear to try and put him to sleep. The spider-like creature rips open the teddy bear, spits in it, and makes it into a cocoon-like spider web. Shortly after Wander chases Capt. Tim down again, Sylvia soon finds the web. She opens it to see the orange stuffing and mistakenly assumes that Wander has been devoured. She mourns greatly over the loss of her best friend and avenges by having the ship to self-destruct to destroy the creature before sadly departing, unaware that Wander is all right and still chasing Capt. Tim.
While Wander continues training Capt. Tim to be his pet, Sylvia, still mourning, vows to move on for Wander. She looks back and is overjoyed to see that Wander is all right and escapes out of an escape pod and returns to the spaceship. She is unable to stop the self-destruct but is able to find Wander and escape with him before the ship's destruction.
Wander and Sylvia are reunited, but Capt. Tim shows up unexpectedly from under Wander's hat. Sylvia, surprised, pushes Capt. Tim and Wander into a second bubble saying she destroyed the ship to get rid of the creature. Wander shows that he had been training Capt. Tim, and that he stole his heart, and then Capt. Tim tries to steal Wander's heart. Sylvia pulls him off Wander and flings him to outside the bubble. Wander tries to make this up as a "love bite" but then comes to understand the point: that Capt. Tim is a "wild animal" who only wanted to destroy him. But still feeling attached to the creature, he plans to find him a home. He and Sylvia turn him into Lord Hater, although the Watchdogs and Commander Peepers are fearful of him. Lord Hater doesn't seem to care, thinking he's the best pet ever. As Wander and Sylvia watch on from a window, Wander says, "You know what they say, Syliva: if you love something, set it free. If it comes back, it's yours. But if it comes back, tries to rip your face off, stabs you a bunch and then lays its eggs inside your chest, it wasn't meant to be."
At the end, Wander ask Sylvia if they could visit some time, and Sylvia says no.
- Jack McBrayer as Wander
- April Winchell as Sylvia
- Keith Ferguson as Lord Hater
- Tom Kenny as Commander Peepers
- Fred Tatasciore as Captain Tim,
- Sam Riegel as Real Captain Tim
- In the promo, when Wander is "walking" Captain Tim, they are running to the right, but in the actual episode they run to the left. This is possibly something to tease the audience before showing what actually happens.
- Shortly before My Best Buddy starts, the timer says the ship will self-destruct in 3 minutes, and counts down to 2:57, but later when Wander chases Captain Tim, the timer says 2:26, even though it was only 17 seconds in between. It should've said 2:40. Also at the same time, the timer doesn't count down by seconds, but by every 1 and six tenths of a second.
- When Wander reaches into his hat to get Sleepy Weepy Beddy Bear, his head shadow doesn't disappear when he takes his hat off.
- When the self-destruct sequence activates, the lights in the ship turn a dull olive color. However at some points, most noticeably during the song sequence, the lights are off and everything's its usual dark tone.
- When Wander and Sylvia leave the ship, Sylvia still has her hunting gear on, but while they see Captain Tim wreck havoc on Lord Hater's ship at the end, Sylvia's hunting gear is taken off, but we don't know where she put it.
- The bow Wander puts on Captain Tim permanently disappears after just one shot with it.
- When Sylvia is about to use the escape pod escape pod, the background in the window isn't moving.
- Shortly before My Best Buddy starts, a timer can be seen above Wander as he counts. However when he turns around and scolds Captain Tim for not finding a good hiding spot, the timer is missing and Captain Tim is in its place. It's possible that Captain Tim hid behind the timer and got rid of it at an unseen moment.
- After Sylvia sees Wander still on the ship and tries to find a way out, the animation of the ship going away in the window is repeated.
- When Wander says "Now, who wants kissies?" the captions say "Now, lunch kissies?".
- In the first shot of Captain Tim chasing the Watchdogs, the captions list Peepers screaming when all of the Watchdogs are screaming.
- While Wander is looking at Captain Tim's name tag, the star on his hat is much smaller than usual.
- While Sylvia is dressing up to save Wander, the shot of her getting a gun ready shows her already wearing gloves. Two scenes later, she puts them on.
- After Wander and Sylvia escape the ship and Captain Tim comes out of Wander's hat, Wander only has two large hair strands instead of three large hair strands and two small ones.
- During the part where Wander tells Captain Tim he'll start training him, the image is blurred slightly.
- Sylvia paints streaks on her face but when she comes upon Sleepy Weepy Beddy Bear mistaking it for Wander, the streaks disappear and never return.
- The episode's name refers to Wander training Captain Tim to be a pet.
- According to Wander, he has always wanted to have a pet.
- There are many references to the movie Aliens, including the acid that eats through the deck plates, Captain Tim's attacks, Sylvia finding a cargo loader when looking for a "biggerer blaster", and the "Get away from him" line. Sylvia's hunting uniform also bears resemblance to Vasquez's hunting uniform