“This looks like the work of crazy old Sideshow Bob.” – Chief Wiggum
“No, chief, Bob’s innocent!  It’s the truth.” – Lisa Simpson
“The truth, huh?  That sounds like the testimony of crazy old Lisa Simpson.” – Chief Wiggum

Sometimes Zombie Simpsons makes it hard to tell the difference between fan service and one of its regularly craptacular plot zigzags.  Was the fact that Sideshow Bob chased Bart and Lisa to the top of a dam at the end of “The Man Who Grew Too Much” supposed to be a shout out to “Brother From the Same Planet”?  Or was it just the only thing that came to mind when they decided that it had to end with him plummeting to his apparent death and having gills?

Whatever the motivation, they chose an ending with a perfectly superficial resemblance to its predecessor.  To get the basics out of the way quickly, “Brother From Another Series” patiently and steadily built up to that climax.  The dam’s construction is the center of the plot, and it is only at the end that we find out that Cecil is the one behind its imminent collapse.  So when Bob and the children are confronted with their own deaths in and above the dam, we know how they got there and what’s going on.  Zombie Simpsons literally just hopped up there:

Here we see Sideshow Bob demonstrating his “grasshopper thighs” on a public street in downtown Springfield.

The very next shot:

Grasshopperus Bob lands squarely in front of Bart and Lisa on top of a dam very far from downtown Springfield.

And just in case there was any doubt about where they were supposed to be, here’s the zoomed out view from right after he lands:

I coulda swore there was a city around here somewhere.  Huh.  Guess not.

Zombie Simpsons has a lot of long running problems with setting and object permanence, but this is pretty impressive even by their standards.  A genetically engineered supervillain leapt from downtown straight to the top of the dam while Bart and Lisa teleported to the same location.  It’s like listening to a four-year-old tell a story:

Adorable Child: And then Sideshow Bob jumped from the street and landed on the dam!
Patient Parent/Guardian: And were Bart and Lisa on top of the dam too, sweetie?
Adorable Child: Yes!

Beyond the basics of how each episode got to the top of the dam, however, are what Sideshow Bob says and does once he’s up there.  Here is the entirety of Bob’s spoken dialogue at the end of “The Man Who Grew Too Much”:

“Python jaw: unhinge!”

“Who am I kidding?  My only exit is a final one.”

“Farewell, Simpsons, and, Lisa, when you’re older, write an autobiographical novel trashing the rest of them.”

“Oh, right, I gave myself gills.”

By any measure that’s very weak, especially when you remember that part of this is him trying to kill himself because of the horrible genetic freak he’s become.  But it gets worse when you realize that the whole thing, basically the entire ending, contains but a single, solitary stab at humor, having Bob tell Lisa to write a novel that trashes her family.  By contrast, here is just some of Bob’s dialogue from the end of “Brother From Another Series”:

“Lisa, you don’t spend ten years as a homicidal maniac without learning a few things about dynamite.”

“You’ve brought shame to this family, Cecil.  Oh, I don’t relish having to write the Christmas letter this year.”

“You’ll live to regret this!  Oh, thanks a lot, now I look crazy.”

“I’m older, I get the top bunk!”

That’s the Sideshow Bob we know and love.  He’s sarcastic, petty and crazy, but still refined and snooty.  And, look, there’s actual jokes, punchlines and witty asides!  Nary a bizarre plot twist or superpower activation to be seen, and I left out plenty of lines that were interactions with other characters (“Bart, how would you like to do something incredibly noble?”, “Do we have to?”, “Yes.”).

Just as importantly, look at what he does in each episode.  At the end of “Brother From Another Series”, he and Lisa start disarming Cecil’s bomb, then he has to save Bart, then he and Bart try to sacrifice themselves to save the town, then he gets thrown back in prison because Chief Wiggum is a dolt, and then he and Cecil get into a brotherly slap fight over the top bunk.  He has all that stuff to do because there was an actual episode prior to his getting up on the dam.  Cecil needs to be thwarted, Bart needed to be saved, and, because this is television and everything has to go back to the way it was, Bob had to go back to prison.

By contrast, “The Man Who Grew Too Much” didn’t really have Bob do anything.  Once he got done bouncing around on his grasshopper thighs and he’s at the top of the dam, what’s left?  He sort of has a confrontation with the teens, but not really.  Lisa quotes Walt Whitman, which makes him want to kill himself all of a sudden.  He jumps.  The end.  The dam itself has nothing to do with anything.  Bob hadn’t previously been thinking about killing himself, so that one came right the fuck out of left field.  The teens are with Homer and Marge for unknown reasons and have no prior reason to want to fight Bob.  The only part of the end that has anything to do with the rest of the episode is Lisa quoting Whitman, but that has nothing to do with the dam, the teens, or Bob’s superpowers.  It’s maniacal and empty because it’s hollower than the shoddy, embezzlement crippled dam Cecil built.