Why are Devils and Other Demonic Beings Pictured with Pitchforks/Tridents?

by Obligatory-Comic

As the title states, why are demonic beings commonly illustrated with pitchforks or tridents? Are the weapons actually pitchforks, tridents, or something different? Is there any historical significance behind this common depiction, and where did this concept begin?

Examples of this phenomenon:

Example 1

Example 2

ImmortalStoryMan

As a follow-up to this, why is death portrayed with a scythe?