Jellyfish vs. Shark fallacy?

I'm racking my brains - there should be a term for this - but I can't think of one.

I will say that:

P) More people throughout history have died from box jellyfish stings than shark attacks

C) Box jellyfish stings are almost always fatal

is a non sequitur. 

If one wishes to defend the claim that X is "almost always" (i.e. 90% of the time, or more frequently than that) the case, they need to do more than show that X is more frequent than Y. In fact, they ought not to compare X and Y at all. They need to look at the total set of cases, and then compare cases of X to those of not-X. In this example, one would need to look at all the times people were stung by box jellyfish, then look at the percentage of those people that died.

So the claim is fallacious; I just lack the appropriate term.

Let's start by making this a clear argument with premises and a conclusion:

P1. More people have died throughout history from box jellyfish stings than from shark attacks.

C. Therefore, box jellyfish stings are almost always fatal. 

This is a clear non sequitur as we are missing information to make that conclusion. Perhaps we can also say that what the argument is suggesting is that:

P1. Shark attacks are almost always fatal (missing information - implied)
P2. Box jellyfish stings are more common then shark attacks.
C. Therefore, Box jellyfish stings are almost always fatal.

The form of this would be:
A's are B.
C's are D.
Therefore, C's are B.

This is a form of the fallacy of four terms . There is no logical connection between the terms because we introduced four of them into the syllogism (shark bite, jellyfish sting, fatal, common).