This source will not include information about sheydim and demons, because there is just way too much for one source sheet!
.......וְאדושם הַשָּׂדֶה, חַיָּה. רַבִּי יוֹסֵי אוֹמֵר, מְטַמְּאוֹת בָּאֹהֶל כָּאָדָם. הַקֻּפָּד וְחֻלְדַּת הַסְּנָיִים, חַיָּה. חֻלְדַּת הַסְּנָיִים, רַבִּי יוֹסֵי אוֹמֵר, בֵּית שַׁמַּאי אוֹמְרִים, מְטַמֵּא כַזַּיִת בְּמַשָּׂא, וְכָעֲדָשָׁה בְּמַגָּע:
.......Wild man-like creatures (Adnei haSadeh) are [in the category of] hayyah (wild animals). Rabbi Yose says: they cause impurity in a tent like a human being. The hedgehog and the bush-mole are [in the category of] hayyah. The bush-mole: Rabbi Yose says in the name of Bet Shammai: an olive's size [of its carcass] renders a person carrying it unclean, and a lentil’s size [of its carcass] renders a person touching it unclean.
This piece of Mishnah is defining which animals are "beheyma" (tamable animals like dogs and cows) and which are "chaya" (wild animals). You may recognize "chaya" from the Yiddish nickname for children, vilde-chaye (lit. wild wild animal), which inspired the book Wild Things.
But what is this creature?
אַבְנֵי הַשָּׂדֶה חַיָּה. ייַסִי עַרְקִי בַּר נַשׁ דְּטוּר הוּא וְהוּא חַיי מִן טִיבוּרֵייהּ אִיפְסַק טִיבוּרֵייהּ לָא חַיי. רִבִּי חָמָא בַּר עוּקְבָּא בְּשֵׁם רִבִּי יוֹסֵי בֶן חֲנִינָה טַעֲמָא דְּרִבִּי יוֹסֵי וְכָל־אֲשֶׁר יִגַּע עַל פְּנֵי הַשָּׂדֶה בְּגָדֵל עַל פְּנֵי הַשָּׂדֶה.
“Avnei haSadeh ‘Field Stones’ is an animal.” Yassi from Arke: It is a mountain man and lives from its navel. If its umbilical cord is cut, it cannot live. Rebbi Ḥama bar Uqba in the name of Rebbi Yose ben Ḥanina: The reason of Rebbi Yose (Num. 19:16): “All that touches [a slain person] on the surface of the field”, when it grows on the field.
This text describes the Adnei/Avnei haSadeh to be a wild creature in the mountains who lives attached to an umbilical cord planted in the earth!
If you want a really intensive exploration on Adnei haSadeh and other fantasy wild creatures that the Rabbis believed existed and were harmless to humans (and if they're kosher!) check out this Modern Orthodox shiur: https://shiurim.yutorah.net/2014/1053/813263.pdf
הדולפנין פרין ורבין כבני אדם מאי דולפנין אמר רב יהודה בני ימא
The dulfanin reproduce like people. The Gemara asks: What are dulfanin? Rav Yehuda says: They are creatures that are called sons of the sea.
If you thought dulfan sounds like dolphin, you're correct! The rabbis got this term from the Greeks, though they perhaps understood it differently.
ה"ג הדולפנין פרים ורבים מבני אדם - שאם בא אדם עליהם מתעברות הימנו:בני ימא - דגים יש בים שחציין צורת אדם וחציין צורת דג ובלע"ז שריינ"א:
This is the correct version: The dulfanin reproduce with people - if a person lies with one of them, they can produce offspring.Sons of the sea - there are fish in the sea that are half in the form of a man and half in the form of a fish. Sirene in old French.
From Mi Yodeya (a Jewish forum):
The Torah says that we may not eat anything without fins and scales if it is among the "sea-life" or of the "beasts of the sea" (Vayikra 11:10) which the Ramban thinks refers specifically to sea creatures that have two legs like those of land-creatures. Assuming that he's talking about mermaids, he implies that they have two legs, instead of fins, and are therefore not kosher.
However, the mermaids that I've seen in Disney movies do not have legs, but do have scales and (I believe) fins. Raavad, though, in his commentary to Toras Kohanim (to the verse above) includes sirens (a.k.a. mermaids) in the list of non-kosher animals. As far as psak halacha, the Aruch Hashulchan (Y.D. 83:10) also states that mermaids are not kosher. His reasoning is that the Torah only permits fish that have fins and scales, and even if a mermaid were to have those features, she is not actually a fish.
As always, be sure to contact your local Orthodox rabbi if this becomes a matter of practical concern.
(90) The first time Adam witnessed the sinking of the sun he was also seized with anxious fears. It happened at the conclusion of the Sabbath, and Adam said, "Woe is me! For my sake, because I sinned, the world is darkened, and it will again become void and without form. Thus will be executed the punishment of death which G-d has pronounced against me!" All the night he spent in tears, and Eve, too, wept as she sat opposite to him. When day began to dawn, he understood that what he had deplored was but the course of nature, and be brought an offering unto G-d, a unicorn whose horn was created before his hoofs, and he sacrificed it on the spot on which later the altar was to stand in Jerusalem.
Here is the origin of the Jewish version of the unicorn. There was once a unicorn in the world. But alas, Adam sacrificed it. This would seem to explain a difficult point with the earlier midrash. If Adam sacrificed an animal then there would be no other descendants of that animal. So what animal must that have been? The unicorn! Another great story.
(ט) אמר לו הדג ליונה: אין אתה יודע שבא יומי להאכל בפיו של לויתן? אמר לו יונה: הוליכני אצלו, אמר יונה ללויתן: בשבילך ירדתי לראות מקום מדורך שאני עתיד ליתן חבל בלשונך ולהעלותך ולזבוח אותך לסעודה הגדולה של צדיקים, הראהו חותמו של אברהם, אמר: הבט לברית, וראה לויתן וברח מפני יונה מהלך שני ימים.......
(9) The fish said to Jonah, Dost thou not know that my day had arrived to be devoured in the midst of Leviathan's mouth? Jonah replied, Take me beside it, and I will deliver thee and myself from its mouth. It brought him next to the Leviathan. (Jonah) said to the Leviathan, On thy account have I descended to see thy abode in the sea, for, moreover, in the future will I descend and put a rope in thy tongue, and I will bring thee up and prepare thee for the great feast of the righteous. (Jonah) showed it the seal of our father Abraham (saying), Look at the Covenant (seal), and Leviathan saw it and fled before Jonah a distance of two days' journey.......
This source describes a legend of the whale who swallowed Jonah. According to this source, the whale was about to be eaten by a Leviathan! To stop this from happening, Jonah leapt out of the fish and 'showed the Leviathan his covenant' (his circumcised penis) and this made the Leviathan swim away!
(52) As leviathan is the king of fishes, so the ziz is appointed to rule over the birds. His name comes from the variety of tastes his flesh has; it tastes like this, zeh, and like that, zeh. The ziz is as monstrous of size as leviathan himself. His ankles rest on the earth, and his head reaches to the very sky.
(53) It once happened that travellers on a vessel noticed a bird. As he stood in the water, it merely covered his feet, and his head knocked against the sky. The onlookers thought the water could not have any depth at that point, and they prepared to take a bath there. A heavenly voice warned them: "Alight not here! Once a carpenter's axe slipped from his hand at this spot, and it took it seven years to touch bottom." The bird the travellers saw was none other than the ziz. His wings are so huge that unfurled they darken the sun. They protect the earth against the storms of the south; without their aid the earth would not be able to resist the winds blowing thence. Once an egg of the ziz fell to the ground and broke. The fluid from it flooded sixty cities, and the shock crushed three hundred cedars. Fortunately such accidents do not occur frequently. As a rule the bird lets her eggs slide gently into her nest. This one mishap was due to the fact that the egg was rotten, and the bird cast it away carelessly. The ziz has another name, Renanin, because he is the celestial singer. On account of his relation to the heavenly regions he is also called Sekwi, the seer, and, besides, he is called "son of the nest," because his fledgling birds break away from the shell without being hatched by the mother bird; they spring directly from the nest, as it were. Like leviathan, so ziz is a delicacy to be served to the pious at the end of time, to compensate them for the privations which abstaining from the unclean fowls imposed upon them.
(א)וַיְדַבֵּר ה׳ אֶל מֹשֶׁה לֵאמֹר, זֹאת הַחַיָּה אֲשֶׁר תֹּאכְלוּ. יְלַמְּדֵנוּ רַבֵּנוּ, כַּמָּה בְּהֵמוֹת טְהוֹרוֹת יֵשׁ בָּעוֹלָם. כָּךְ שָׁנוּ רַבּוֹתֵינוּ, עֶשֶׂר בְּהֵמוֹת הֵן, אַיָּל וּצְבִי וְיַחְמוּר וְאַקּוֹ וְדִישׁוֹן וּתְאוֹ וָזָמֶר (דברים יד, ה), שׁוֹר שֵׂה כְשָׂבִים וְשֵׂה עִזִּים (דברים יד, ד). יוֹתֵר מֵאֵלֶּה אֵין בָּעוֹלָם. ........ תֵּדַע, שֶׁלֹּא נִצְטַוָּה הַשְּׁחִיטָה הַזּוֹ אֶלָּא כְּדֵי לְצָרֵף אֶת יִשְׂרָאֵל, כִּי לֶעָתִיד לָבֹא עוֹשֶׂה סְעוּדָה לַצַּדִּיקִים מִן הַבְּהֵמָה וְלִוְיָתָן וְאֵין שָׁם שְׁחִיטָה. תֵּדַע לְךָ, לִוְיָתָן בְּרִיָּה מְשֻׁנָּה הוּא, וְהַמַּלְאָכִים יָגוּרוּ מִמֶּנּוּ, שֶׁנֶּאֱמַר: מִשֵּׂתוֹ יָגוּרוּ אֵלִים (איוב מא, יז). וְאִם הֵם זוֹרְקִין עָלָיו כַּמָּה רְמָחִים שֶׁל בַּרְזֶל, כְּתֶבֶן הוּא חוֹשְׁבָן, שֶׁנֶּאֱמַר: יַחְשֹׁב לְתֶבֶן בַּרְזֶל (איוב מא, יט). וְכֵן בְּהֵמוֹת שָׂדַי קָשֶׁה, שֶׁהוּא רוֹבֵץ עַל אֶלֶף הָרִים, שֶׁנֶּאֱמַר: בְּהֵמוֹת בְּהַרְרֵי אֶלֶף (תהלים נ, י). וְהֵיכָן הֵן נִשְׁחָטִין. אֶלָּא זֶה לָזֶה מִזְדַּוְגִין שְׁנֵיהֶם, שֶׁנֶּאֱמַר: אֶחָד בָּאֶחָד יִגָּשׁוּ (איוב מא, ח). בְּהֵמוֹת יִגַּשׁ בַּלִּוְיָתָן וְאוֹחֵז בְּקַרְנָיו וּבוֹקֵעַ. וְלִוְיָתָן הֵפֶךְ יִהְיֶה מִיתָתוֹ, שֶׁמַּכֶּה אוֹתוֹ בִּזְנָבוֹ וְהוֹרְגוֹ, וְהַצַּדִּיקִים הוֹלְכִין וְנוֹטְלִין מָנוֹת מָנוֹת. מִכָּאן שְׁחִיטָה. אֶלָּא בִּשְׁבִיל לִבְדֹּק וּלְצָרֵף אֶת יִשְׂרָאֵל.
(1) (Lev. 11:1-2) “Then the Lord spoke unto Moses…, saying, ‘… these are the creatures that you may eat….’” Let our master instruct us: How many [types of] pure animals are there are in the world? Thus have our masters taught: There are ten beasts: “The deer, the gazelle, the roebuck, the wild goat, the ibex, the antelope, the mountain sheep”; (Deut. 14:5) “the ox, the sheep and the goat” (Deut. 14:4). There are no more than these in the world. ....... Know that this ritual slaughter was given only to purify (rt.: tsrp) Israel. As in the future to come, the Holy One, blessed be He, will make a meal for the righteous from the behemoth and the leviathan, and there is no ritual slaughter there. Know that the leviathan is an unusual creature, and the angels fear him, as stated (in Job 41:17), “From his rising do the powers fear.” And if they throw many spears of iron upon him, he considers them like straw, as stated (in Job 41:19), “He considers iron like straw.” And also the behemoths of my fields are harsh, as it crouches on a thousand mountains as stated (in Psalms 50:10), “the behemoths on a thousand mountains.” And [so] how are they slaughtered? Rather, they come and fight, one with the other, as stated (in Job 41:8), “One approaches to the other.” The behemoths approach the leviathan and hold him by his horn and split him, and the leviathan’s death [that he inflicts] will be the opposite, as he smites him with his tail and kills him. [Then] the righteous ones go and all take portions. From here [we see] that ritual slaughter was given only to examine and to purify (rt.: tsrp) Israel.
Omitted a small tangent in the middle of this source for the sake of time and understanding!
If you would like to learn more about the halakhic ramifications of vampires/zombies, check out this source: https://www.sefaria.org/sheets/113056?lang=bi
Also, more exploration on monsters and creatures, including estries (vampires/succubi), werewolves, dragons, and giants! https://www.sefaria.org/sheets/469622?lang=bi