In Genesis, there is some type evil serpent thing that talks and is deceitful. Job talks about some type accuser. If you need to look to see if there is a demon, look no further than the white House, you will find the most evil demon alive.
Genesis Chapter 3 בְּרֵאשִׁית
א וְהַנָּחָשׁ, הָיָה עָרוּם, מִכֹּל חַיַּת הַשָּׂדֶה, אֲשֶׁר עָשָׂה יְהוָה אֱלֹהִים; וַיֹּאמֶר, אֶל-הָאִשָּׁה, אַף כִּי-אָמַר אֱלֹהִים, לֹא תֹאכְלוּ מִכֹּל עֵץ הַגָּן. 1 Now the serpent was more subtle than any beast of the field which the LORD God had made. And he said unto the woman: 'Yea, hath God said: Ye shall not eat of any tree of the garden?'
ב וַתֹּאמֶר הָאִשָּׁה, אֶל-הַנָּחָשׁ: מִפְּרִי עֵץ-הַגָּן, נֹאכֵל. 2 And the woman said unto the serpent: 'Of the fruit of the trees of the garden we may eat;
ג וּמִפְּרִי הָעֵץ, אֲשֶׁר בְּתוֹךְ-הַגָּן--אָמַר אֱלֹהִים לֹא תֹאכְלוּ מִמֶּנּוּ, וְלֹא תִגְּעוּ בּוֹ: פֶּן-תְּמֻתוּן. 3 but of the fruit of the tree which is in the midst of the garden, God hath said: Ye shall not eat of it, neither shall ye touch it, lest ye die.'
ד וַיֹּאמֶר הַנָּחָשׁ, אֶל-הָאִשָּׁה: לֹא-מוֹת, תְּמֻתוּן. 4 And the serpent said unto the woman: 'Ye shall not surely die;
ה כִּי, יֹדֵעַ אֱלֹהִים, כִּי בְּיוֹם אֲכָלְכֶם מִמֶּנּוּ, וְנִפְקְחוּ עֵינֵיכֶם; וִהְיִיתֶם, כֵּאלֹהִים, יֹדְעֵי, טוֹב וָרָע. 5 for God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as God, knowing good and evil.'
ו וַתֵּרֶא הָאִשָּׁה כִּי טוֹב הָעֵץ לְמַאֲכָל וְכִי תַאֲוָה-הוּא לָעֵינַיִם, וְנֶחְמָד הָעֵץ לְהַשְׂכִּיל, וַתִּקַּח מִפִּרְיוֹ, וַתֹּאכַל; וַתִּתֵּן גַּם-לְאִישָׁהּ עִמָּהּ, וַיֹּאכַל. 6 And when the woman saw that the tree was good for food, and that it was a delight to the eyes, and that the tree was to be desired to make one wise, she took of the fruit thereof, and did eat; and she gave also unto her husband with her, and he did eat.
ז וַתִּפָּקַחְנָה, עֵינֵי שְׁנֵיהֶם, וַיֵּדְעוּ, כִּי עֵירֻמִּם הֵם; וַיִּתְפְּרוּ עֲלֵה תְאֵנָה, וַיַּעֲשׂוּ לָהֶם חֲגֹרֹת. 7 And the eyes of them both were opened, and they knew that they were naked; and they sewed fig-leaves together, and made themselves girdles.
ח וַיִּשְׁמְעוּ אֶת-קוֹל יְהוָה אֱלֹהִים, מִתְהַלֵּךְ בַּגָּן--לְרוּחַ הַיּוֹם; וַיִּתְחַבֵּא הָאָדָם וְאִשְׁתּוֹ, מִפְּנֵי יְהוָה אֱלֹהִים, בְּתוֹךְ, עֵץ הַגָּן. 8 And they heard the voice of the LORD God walking in the garden toward the cool of the day; and the man and his wife hid themselves from the presence of the LORD God amongst the trees of the garden.
ט וַיִּקְרָא יְהוָה אֱלֹהִים, אֶל-הָאָדָם; וַיֹּאמֶר לוֹ, אַיֶּכָּה. 9 And the LORD God called unto the man, and said unto him: 'Where art thou?'
י וַיֹּאמֶר, אֶת-קֹלְךָ שָׁמַעְתִּי בַּגָּן; וָאִירָא כִּי-עֵירֹם אָנֹכִי, וָאֵחָבֵא. 10 And he said: 'I heard Thy voice in the garden, and I was afraid, because I was naked; and I hid myself.'
יא וַיֹּאמֶר--מִי הִגִּיד לְךָ, כִּי עֵירֹם אָתָּה; הֲמִן-הָעֵץ, אֲשֶׁר צִוִּיתִיךָ לְבִלְתִּי אֲכָל-מִמֶּנּוּ--אָכָלְתָּ. 11 And He said: 'Who told thee that thou wast naked? Hast thou eaten of the tree, whereof I commanded thee that thou shouldest not eat?'
יב וַיֹּאמֶר, הָאָדָם: הָאִשָּׁה אֲשֶׁר נָתַתָּה עִמָּדִי, הִוא נָתְנָה-לִּי מִן-הָעֵץ וָאֹכֵל. 12 And the man said: 'The woman whom Thou gavest to be with me, she gave me of the tree, and I did eat.'
יג וַיֹּאמֶר יְהוָה אֱלֹהִים לָאִשָּׁה, מַה-זֹּאת עָשִׂית; וַתֹּאמֶר, הָאִשָּׁה, הַנָּחָשׁ הִשִּׁיאַנִי, וָאֹכֵל. 13 And the LORD God said unto the woman: 'What is this thou hast done?' And the woman said: 'The serpent beguiled me, and I did eat.'
יד וַיֹּאמֶר יְהוָה אֱלֹהִים אֶל-הַנָּחָשׁ, כִּי עָשִׂיתָ זֹּאת, אָרוּר אַתָּה מִכָּל-הַבְּהֵמָה, וּמִכֹּל חַיַּת הַשָּׂדֶה; עַל-גְּחֹנְךָ תֵלֵךְ, וְעָפָר תֹּאכַל כָּל-יְמֵי חַיֶּיךָ. 14 And the LORD God said unto the serpent: 'Because thou hast done this, cursed art thou from among all cattle, and from among all beasts of the field; upon thy belly shalt thou go, and dust shalt thou eat all the days of thy life.
טו וְאֵיבָה אָשִׁית, בֵּינְךָ וּבֵין הָאִשָּׁה, וּבֵין זַרְעֲךָ, וּבֵין זַרְעָהּ: הוּא יְשׁוּפְךָ רֹאשׁ, וְאַתָּה תְּשׁוּפֶנּוּ עָקֵב. {ס} 15 And I will put enmity between thee and the woman, and between thy seed and her seed; they shall bruise thy head, and thou shalt bruise their heel.' {S}
טז אֶל-הָאִשָּׁה אָמַר, הַרְבָּה אַרְבֶּה עִצְּבוֹנֵךְ וְהֵרֹנֵךְ--בְּעֶצֶב, תֵּלְדִי בָנִים; וְאֶל-אִישֵׁךְ, תְּשׁוּקָתֵךְ, וְהוּא, יִמְשָׁל-בָּךְ. {ס} 16 Unto the woman He said: 'I will greatly multiply thy pain and thy travail; in pain thou shalt bring forth children; and thy desire shall be to thy husband, and he shall rule over thee.' {S}
יז וּלְאָדָם אָמַר, כִּי-שָׁמַעְתָּ לְקוֹל אִשְׁתֶּךָ, וַתֹּאכַל מִן-הָעֵץ, אֲשֶׁר צִוִּיתִיךָ לֵאמֹר לֹא תֹאכַל מִמֶּנּוּ--אֲרוּרָה הָאֲדָמָה, בַּעֲבוּרֶךָ, בְּעִצָּבוֹן תֹּאכְלֶנָּה, כֹּל יְמֵי חַיֶּיךָ. 17 And unto Adam He said: 'Because thou hast hearkened unto the voice of thy wife, and hast eaten of the tree, of which I commanded thee, saying: Thou shalt not eat of it; cursed is the ground for thy sake; in toil shalt thou eat of it all the days of thy life.
יח וְקוֹץ וְדַרְדַּר, תַּצְמִיחַ לָךְ; וְאָכַלְתָּ, אֶת-עֵשֶׂב הַשָּׂדֶה. 18 Thorns also and thistles shall it bring forth to thee; and thou shalt eat the herb of the field.
יט בְּזֵעַת אַפֶּיךָ, תֹּאכַל לֶחֶם, עַד שׁוּבְךָ אֶל-הָאֲדָמָה, כִּי מִמֶּנָּה לֻקָּחְתָּ: כִּי-עָפָר אַתָּה, וְאֶל-עָפָר תָּשׁוּב. 19 In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken; for dust thou art, and unto dust shalt thou return.'
כ וַיִּקְרָא הָאָדָם שֵׁם אִשְׁתּוֹ, חַוָּה: כִּי הִוא הָיְתָה, אֵם כָּל-חָי. 20 And the man called his wife's name Eve; because she was the mother of all living.
כא וַיַּעַשׂ יְהוָה אֱלֹהִים לְאָדָם וּלְאִשְׁתּוֹ, כָּתְנוֹת עוֹר--וַיַּלְבִּשֵׁם. {פ} 21 And the LORD God made for Adam and for his wife garments of skins, and clothed them. {P}
כב וַיֹּאמֶר יְהוָה אֱלֹהִים, הֵן הָאָדָם הָיָה כְּאַחַד מִמֶּנּוּ, לָדַעַת, טוֹב וָרָע; וְעַתָּה פֶּן-יִשְׁלַח יָדוֹ, וְלָקַח גַּם מֵעֵץ הַחַיִּים, וְאָכַל, וָחַי לְעֹלָם. 22 And the LORD God said: 'Behold, the man is become as one of us, to know good and evil; and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever.'
כג וַיְשַׁלְּחֵהוּ יְהוָה אֱלֹהִים, מִגַּן-עֵדֶן--לַעֲבֹד, אֶת-הָאֲדָמָה, אֲשֶׁר לֻקַּח, מִשָּׁם. 23 Therefore the LORD God sent him forth from the garden of Eden, to till the ground from whence he was taken.
כד וַיְגָרֶשׁ, אֶת-הָאָדָם; וַיַּשְׁכֵּן מִקֶּדֶם לְגַן-עֵדֶן אֶת-הַכְּרֻבִים, וְאֵת לַהַט הַחֶרֶב הַמִּתְהַפֶּכֶת, לִשְׁמֹר, אֶת-דֶּרֶךְ עֵץ הַחַיִּים. {ס} 24 So He drove out the man; and He placed at the east of the garden of Eden the cherubim, and the flaming sword which turned every way, to keep the way to the tree of life. {S}