Jewish Demons and Monsters!

(21) God created the great sea monsters, and all the living creatures of every kind that creep, which the waters brought forth in swarms, and all the winged birds of every kind. And God saw that this was good.

(9) Aaron shall bring forward the goat designated by lot for יהוה, which he is to offer as a sin offering;(10) while the goat designated by lot for Azazel shall be left standing alive before יהוה, to make expiation with it and to send it off to the wilderness for Azazel.

(15) So Jeshurun grew fat and kicked—
You grew fat and gross and coarse. They forsook the God who made them And spurned the Rock of their support.(16) They incensed [God] with alien things, vexed [God] with abominations. (17) They sacrificed to demons, no-gods, Gods they had never known, New ones, who came but lately, Who stirred not your forebears’ fears.*(18) You neglected the Rock who begot you,
Forgot the God who labored to bring you forth. (19) יהוה saw and was vexed
And spurned these sons and daughters. (20) [God] said: I will hide My countenance from them, And see how they fare in the end. For they are a treacherous breed, Children with no loyalty in them.

(36) They worshiped their idols, which became a snare for them.(37) Their own sons and daughters they sacrificed to demons.(38) They shed innocent blood, the blood of their sons and daughters, whom they sacrificed to the idols of Canaan; so the land was polluted with bloodguilt.(39) Thus they became defiled by their acts, debauched through their deeds.

(15) For you have said, “We have made a covenant with Death, Concluded a pact with Sheol. When the sweeping flood passes through, It shall not reach us; For we have made falsehood our refuge, Taken shelter in treachery.”

(6) 9 magical things were created on the eve of the first Shabbat, and they are: [1] the mouth of the earth when it swallows up Korach in the Torah, [2] the magical well that follows the Israelites in the desert, [3] the talking donkey from the Torah, [4] the rainbow, [5] the manna (the magical food that falls from the sky in the Passover story), [6] the staff [of Moses] which parted the Red Sea, [7] the letters of the Torah, [9] the words of the Torah, [10] and the tablets of the 10 commandments. And some also say demons.

It was taught that Abba Binyamin said: If the eye was able to see, no living creature would be able to stay calm in the presence of the huge numbers of demons they would see and continue to live unaffected by them.Similarly, Abaye said: Demons are more numerous than we are and they stand over us like mounds of dirt surround a pit.Rav Huna said: Each and every one of us has a thousand demons to their left and ten thousand to their right. God protects us from these demons, as it says in the verse from Psalm 91:7: “A thousand may fall at your side, and ten thousand at your right hand; they will not approach you”

If we can't see demons, how can we tell their effects on us?

Rava said: The crowding and big lines that happen at the gatherings for Torah study is because of the demons; when our knees are fatigued even though we did not exert ourselves is because of the demons;
when clothes of the Rabbis get holes in them, even though they do not engage in physical work, is because of friction from brushing up against the demons;
and when our feet are in pain is because of the demons.

One who seeks to know that the demons exist should place fine ashes or flour around his bed, and in the morning the demons’ footprints appear like chickens’ footprints, in the flour. One who seeks to see them should take a dead black cat, born to a firstborn female black cat, burn it in the fire, grind it and place it in their eyes, and they will see them! They must then place the ashes in an iron tube sealed with an iron seal to prevent the demons from stealing. They must seal the opening so they will not be harmed. Rav Bei'vai bar Abaye performed this procedure, saw the demons, and was harmed. The Rabbis prayed for mercy on his behalf and he was healed.

We learned in the mishna that even with regard to the poorest of Jews, the charity distributors should not give him less than four cups of wine. But wasn’t it taught in a baraita (an unrecorded teaching): A person should not eat pairs, (i.e., an even number of food items); and he should not drink pairs of cups; and he should not wipe himself with pairs; and he should not attend to his sexual needs in pairs. The concern was that one who uses pairs exposes himself to sorcery or demons. Why would the Sages require one to drink an even number of cups and thereby place himself in a position of danger?Rav Naḥman said that the verse said: “It was a night of watching to the Lord” (Exodus 12:42), which indicates that Passover night is a night that remains guarded from demons and harmful spirits of all kinds. Therefore, there is no cause for concern about this form of danger on this particular night.