Reference for Chullin 3:3
וְאֵלּוּ טְרֵפוֹת בָּעוֹף. נְקוּבַת הַוֶּשֶׁט, פְּסוּקַת הַגַּרְגֶּרֶת, הִכַּתָּהּ חֻלְדָּה עַל רֹאשָׁהּ, מְקוֹם שֶׁעוֹשֶׂה אוֹתָהּ טְרֵפָה, נִקַּב הַקֻּרְקְבָן, נִקְּבוּ הַדַּקִּין, נָפְלָה לָאוּר וְנֶחְמְרוּ בְנֵי מֵעֶיהָ, אִם יְרֻקִּים, פְּסוּלִין. אִם אֲדֻמִּים, כְּשֵׁרִים. דְּרָסָהּ, וּטְרָפָהּ בַּכֹּתֶל, אוֹ שֶׁרִצְּצַתָּהּ בְּהֵמָה וּמְפַרְכֶּסֶת, וְשָׁהֲתָה מֵעֵת לְעֵת וּשְׁחָטָהּ, כְּשֵׁרָה:
The following defects render fowl Terefá: when the œsophagus is perforated; when the trachea is torn off; when a weasel bit it on the head, in a place where it may render it Terefá [viz. near the brain]; when the stomach or thin intestines are perforated; when it had fallen into the fire; when its viscera had become scorched, if they had turned yellow it is Terefá, but when they remained red it is Cashér; when a person had trodden on it, or knocked it against a wall, or that it was trodden upon by cattle, and it struggles and lives twenty-four hours after the accident [and was then slaughtered], it is Cashér.