I was learning Sefer Hamitzvot with my dad last night and, when we came across mitzvah #256, I was curious; do we have any idea what the yadua bone is? It is a bone of a bird which grows from a long cord from the ground connected to the navel similar to squash, its form is like a man's form, Rambam calls it a bird but Sefer Hachinuch seems to suggest it is a stationary plant-like creature, and it devours everything it can reach with its cord. One would place it in his mouth, have an epilepsy, and predict the future. Here are the links to the mitzvot regarding this creature: https://www.sefaria.org/Sefer_HaChinukh.514.1?lang=en&with=About&lang2=en https://www.sefaria.org/Sefer_HaChinukh.257.1?lang=bi&with=all&lang2=en
There is a lot that has been written about the Yaduah / Adnei HaTzadeh, I will attempt to provide more details about what exactly it is and not whether or not it is to be regarded as extinct or not.
As pointed out in the Sefer HaChinuch, the starting point is to be found in Mishnah Kilayim 8:5 It talks about having different species pulling a wagon and whether it is to be regarded as Kilyaim or not. It writes over there:
וְאַדְנֵי הַשָּׂדֶה, חַיָּה
And the Adnei HaTzadeh is to be regarded as chayah - i.e. a wild animal (and therefore the laws of kilayim are applicable to it)
The Bartenura tells us that it is also called the 'Yaduah' and adds some more ways to categorise it. He writes as follows:
אדני השדה. חיה הגדלה בשדות, וכמין חבל גדול יוצא מן הארץ שגדלה בו אותה חיה, ושמה ידוע, והוא ידעוני הכתוב בתורה, ומחובר בטבורו באותו חבל היוצא מן הארץ, וצורתו צורת אדם בפרצוף וידים ורגלים ואין כל בריה רשאה לקרב אליו כי הוא הורג וטורף כל הקרב אליו. וכשרוצים לצוד אותו מורים בחצים בחבל עד שנפסק וצועק בקול מר ומת מיד, ואליו רמז באיוב כי עם אבני השדה בריתך
Adnei HaTzadeh - It was a large wild animal in the fields and a type of large cord goes out from the ground and into the creature and its name is the Yaduah - and this is the 'Yidoni'1 that the Torah writes about. And it is connected by the navel by the same cord that comes out the ground, and its shape is a human form in the face and hands and feet, and no creature can draw near to it because it kills and tears apart all those who approach it. And when they want to hunt it, they have to fire arrows at the cord until it severs and cries out a bitter voice and dies immediately. And there is a hint to it in Iyov - "For you will have a pact with the rocks in the field".
(Also refer to the Tosafos Yom Tov about the danger of drawing too near)
The Rambam in his Peirush Hamishnayos notes how this creature is of a man-like form and that it converses constantly but is not understandable. However he concludes interestingly by stating:
ומגידים מעניניו בספרים דברים רבים
It is talked about in many books
This creature also makes a cameo in the plague of Arov (Wild Beasts). The pasuk in Shemos 8:17 writes:
כִּ֣י אִם־אֵינְךָ֮ מְשַׁלֵּ֣חַ אֶת־עַמִּי֒ הִנְנִי֩ מַשְׁלִ֨יחַ בְּךָ֜ וּבַעֲבָדֶ֧יךָ וּֽבְעַמְּךָ֛ וּבְבָתֶּ֖יךָ אֶת־הֶעָרֹ֑ב וּמָ֨לְא֜וּ בָּתֵּ֤י מִצְרַ֙יִם֙ אֶת־הֶ֣עָרֹ֔ב וְגַ֥ם הָאֲדָמָ֖ה אֲשֶׁר־הֵ֥ם עָלֶֽיהָ׃
For if you do not let My people go, I will let loose swarms of insects against you and your courtiers and your people and your houses; the houses of the Egyptians, and the very ground they stand on, shall be filled with swarms of insects.
This is understood by some commentaries as a reference to the Adnei HaTzadeh, as due to its umbilical cord that rooted it to the ground, it could only travel whilst moving along the ground that it was on. (Refer to the Vilna Gaon in Divrei Eliyahu - last paragraph on the page, The Sefer Chanukas HaTorah - 59 and the Sefer Nitzutzei Shimshon).
1 It is worth noting the Rashi over there which writes:
אל תפנו. אַזְהָרָה לְבַעַל אוֹב וְיִדְּעוֹנִי; בַּעַל אוֹב זֶה פִּיתוֹם הַמְדַבֵּר מִשֶּׁחְיוֹ, וְיִדְּעוֹנִי הַמַּכְנִיס עֶצֶם חַיָּה שֶׁשְּׁמָה יַדּוּעַ לְתוֹךְ פִּיו וְהָעֶצֶם מְדַבֵּר (סנהדרין ס"ה):
אל תפנו DO NOT TURN [TO THE אבת NOR TO THE ידענים] — This is a warning addressed to the necromancers and the charmers themselves (not to the people who consult these tricksters). The בעל אוב, the controller of the spirit אוב, as the necromancer is called (cf. I Samuel 28:7), is identical with the פיתום (in Greek: πύξωυ); he is one who speaks out of his arm-pit; ידעני is one who puts a bone of an animal the name of which is ידוע into his mouth and the bone speaks (Sanhedrin 65b).
So this Rashi and the Gemara in Sanhedrin (linked) refer to the point that the Sefer HaChinuch alludes to, about somehow getting hold of a bone from this creature with which one can insert in ones mouth, and the bone speaks on its own.