You mix plural and singular here - does this pump all creatures or one creature you control?

I'd suggest using "Whenever a creature dies"

Whoops, I was debating between whether this would only pump itself or your whole field and decided it to be the whole field. I didn't doublecheck my work though.

This card is supposed to be supported with the Salvage mechanic, so creatures would be entering your graveyard from the library, hence my choice of wording.

In that case the correct wording is "Whenever a creature card is put into a graveyard from anywhere, ...". If you talk about "creature" without anything else this automatically means "creature permanent".

The "from anywhere" makes certain that it is unambiguous that not only objects that were previously cards are counted, but also permanents and spells that are not referred to as cards before entering the graveyard.

If you want the trigger to also count spells and permanents that aren't represented by cards, you'll have to call them otu individually ("Whenever a token creature dies or a creature card is put into the graveyard from anywhere") or do the reverse ("Whenever a creature dies or a creature card is put into your graveyard from the battlefield").

I don't recall the token density of this set, but usually you would choose the wording that doesn't synergize with tokens and is simpler.