For example, I'm having a political debate and I am bringing up facts, like under this government the energy prices rose this amount, the unemployment rate is higher then ever and the government had this and this corruption scandals.
To which my opponent replies: Oh yes, and 90% of the people got leprosy since this government is in power and they are personally infecting people with Covid every night.
Is this a fallacy?
Maybe, but probably not.
What you have presented may be a logical fallacy, but there is a degree of absurdity of the counterclaim which suggests it's more a rhetorical technique than a logical fallacy. I believe it's better to consider this as a hyperbole. It's hard to believe that your opponent intended you to take the claim literally. From hyperbole (WP):
As a figure of speech, it is usually not meant to be taken literally.
Oh yes, and 90% of the people got leprosy since this government is in power and they are personally infecting people with Covid every night.
Conifold has reasonably identified the straw man fallacy of informal logic. But, we do have to worry about whether or not the claim meets the definition of the criterion " appears to refute the original argument". I think in educated company, no one would take seriously the claim that leprosy and SARS have anything in common. Since you've probably made no claims about leprosy and the government personally conveying the disease, among a crowd with a basic understanding of germ theory, it might be better to consider this an instance of rhetorical hyperbole. (And hyperbolic claims misattributed to a claimant often end in ad hominem).
We have two distinct traditions for examing claims, that of informal logic and that of rhetoric, and of course, there is a lot of overlap. Sometimes, claims don't fit nicely in categories. I believe this to be the case. One can look at language from the cogntivist perspectives which emphasizes the truth and the logical structure that inheres to the language. But one can also seek to find how language in argumentation might seek to exploit cognitive biases. I believe that while it's plausible to characterize this as a straw man, it might be better to see this as an attempt to use humor, likely building to be at your expense, to undermine the argument through emotional persuasion.
Ultimately, the context of the counterclaim will determine whether this is more of an informal fallacy (your opponent genuinely attempts to confuse hearers with an attack on an argument other than the one you made) or whether the absurdity is more of an attempt to show you disregard as a claimant by stuffing your mouth with counterclaims that are obviously silly. One might even want to consider if there's an audience at all when considering the nature of this counterclaim which, of course, is not to rule out that your partner in argument is not trying to deceive themselves. Rationalization is a normal occurrence in emotively charged topics of debate.
It's not a strawman or non-sequitur fallacy unless the opponent explicitly tells you that your argument,
under this government the energy prices rose this amount
is invalid because of,
90% of the people got leprosy since this government is in power
However, if you want to take the implicit meaning of the opponents expression than you may say he wanted to demean your argument but there would be problem because at the same time the opponent may have another implicit position by the same expression that is, to let you know that your argument (government to employment rate) is a non-sequitur just like his analogy government to leprosy rate is a non-sequitur.
In my opinion, it would be better to ask him back to clarify what he meant by that before saying he did a fallacy.
