Today’s Macanudo, twice:
“It was nice while it lasted.” Okay, I’ll buy the pairing. Both are sweetly regretful but have just a tiny bit of a sting, don’t you think?
But now, today’s Baldo, also twice:
Now at first this looks like something we’ve seen a few times with Baldo: A pun or language-dependent joke in the English version, and then a reduction to a univocal expression in the Spanish version with no attempt to preserve the polysemy needed for the pun.
But not this time!
The key is in hachacento, which does not register as a recognized or translatable Spanish word, at least by Google Translate. But looking at parts:
hatchet ==> hacha
accent ==> acento
So we do get both axe and accent! (But not sent ==> enviad{o/a}. But who cares at this point!)
P.S. Don’t forget to stop and smell the noises in panel 3.
Comics I Don't Understand 
So, for the Maca, they’ve decided to use not a translation but an entire substitution, with a very similar higher-level “meaning” but not the same linguistic meaning. (A description that holds irregardless of whether the Spanish or English or neither was made first.)
And that’s their prerogative, isn’t it? It seems just fine to me.
Oh of course, Dana, I don’t think anyone here would be challenging the propriety of doing it that way! Just observing it as an interesting choice.
The Macanudo puzzles me, especially in English. A “fair-weather friend” is one who is only friendly when convenient. It implies that the butterfly is being disingenuous, or that some negative externality has caused it to leave its perch atop the cat’s head.
And if that was the original, using a different phrase for Spanish makes sense if Spanish doesn’t have the same idiom. But the Spanish phrase has a different connotation. It treats the butterfly as more of an ephemeral happening rather than a conscious agent with its own motivations. And the translation “It was nice while it lasted” would have worked just fine in English, so the “fair-weather friend” version seems less apropos.
Then there’s Baldo.
While “hachacento” is at least a stab at a pun, it’s not very good. It’d be like saying in English (assuming it was introduced as a hatchet and not an axe), “I’ve always wanted a foreign hatchetchcent”. The Spanish words combine slightly better thanks to the overlapping syllable, but either way it’s just a random portmanteau. There’s no reason to combine the words except to be able to claim there’s a pun, when there really isn’t.
Of course, given the context, maybe that was the point. The joke in the English version is actually good wordplay. In the Spanish version, it’s obvious he’s not as funny as he thinks he is.
polysemy
Ooh, a new word! A non-slang new word! Thanks, Mitch