Is there any other pokedex entry of how a Pokemon could die?

Question

In charmander’s pokedex entry it says it's tail flame is it's life energy so if it's burns out it'll die,and spoink’s says how it jumps for it's heart and when it stops it dies.

Answer 1

I couldn't find any others exactly like the examples you gave, but a lot of Ghost Pokemon (and some others) kill and steal souls, but I think that is different than what you are asking.

The closest I could find to what I think you meant is Cubone:
>It lost its mother after birth. I wear's its mothers skull, never revealing its true face.

-Pokémon Crystal Pokedex Entry

This is purely theory, as it never comes out and says it, but if Cubone 1) wears its mother's skull, and 2) never shows its true face, then presumably its mother dies as a direct result of giving birth. I would assume that its mother is Marowak, so therefore if Marwak gives birth it dies.

Of course playing through any of the games fom Gen II onwards completely disproves this, as Marowak is still there after breeding, but the above statement is still the logical conclusion from the pokedex entries alone.

As for entries exactly like Charmander and Spoink, I couldn't find any, though.

Answer 2

Well this isn't exactly a Pokemon dying, it is the death of what is essentially a Pokemon

*That makes absolutely no sense

Hear my out: this is Yamask's pokedex entry from White and BW2:

"These Pokémon arose from the spirits of people interred in graves in past ages. Each retains memories of its former life."

Yamask has died at one point, and is now, essentially, dead.

There is also an instance where a Pokemon's death is mentioned, but not in its own pokedex

Tailow's Sapphire entry states:

"Taillow is young - it has only just left its nest. As a result, it sometimes becomes lonesome and cries at night. This Pokémon feeds on Wurmple that live in forests."

As shown here, Taillow kills and consumes Wurmple regularly.

Similarly, Heatmor's white pokedex entry states

"Using their very hot, flame-covered tongues, they burn through Durant's steel bodies and consume their insides."

Ouch. Yup that's pretty much it right there.

So yes, there are other instances of Pokemon death mentioned in the pokedex, but typically they are not as direct as charmander's or spoink's, There may be more than these as well, but hope this helps.