Does selenium sulfate corrode or otherwise react with metals?
Yes, selenium sulfide is well known and it is used in anti-dandruff shampoo but other sulfur-containing selenium compounds are not really well known. Selenium sulfate, properly selenium(II) sulfate, $\ce{SeSO4}$ is unknown to the best of my knowledge. The analogous tellurium compound has been synthesized recently, but still it is not a proper sulfate compound, rather it is actually an oxide-sulfate mixture type of compound.

In case you are wondering whether selenium sulfate will be obtained by reacting selenium with sulfuric acid, then you are wrong. Selenium and sulfuric acid would react to form a mixture of acids (selenous and selenic acid) but they would all disproportionate to selenium dioxide, sulfur dioxide and water.


$$\ce{Se + 2H2SO4 -&gt;[\Delta] SeO2 + 2SO2 + 2H2O}$$

Selenium sulfite or properly selenium sulfoxide, $\ce{SeSO3}$, is however known.

So, selenium sulfate is a fictitious compound and thus used in the cartoon.