Mishnayos Bava Kamma Perek 1 Mishnah 4

There are five damage-causing acts that an animal can perform twice and remain innocuous even when its owner was warned each time to prevent it from doing so. After the third time, the animal is rendered forewarned. In such cases, the owner is liable to pay only half of the damages. And there are five damage-causing acts for which an animal is considered forewarned, at times even if it had never caused damage in that manner. In such cases the owner is liable to pay the full cost of the damage. An animal is not considered forewarned with regard to Goring, i.e., not for goring with its horns, nor for pushing with its body, nor for biting, nor for crouching upon items in order to damage them, nor for kicking. In these cases the animal is considered to be innocuous and its owner is liable for only half of the damages. Concerning acts of damage performed with the tooth, the animal is considered forewarned with regard to eating that which is fitting for it to eat. Concerning acts of damage performed with the foot, the animal is considered forewarned with regard to breaking items while walking. And there is a forewarned ox, which gored three times and each time his owner was warned to safeguard his ox from doing so. And there is an ox that causes damage to the property of the injured party while on the property of the injured party. And there is the person, i.e., any damage done by a person. In all of these cases the one who caused the damage is considered to be forewarned, resulting in the obligation to pay the full cost of the damage. The mishna presents the halakha for wild animals: The wolf; the lion; the bear; the leopard; the bardelas, the meaning of which the Gemara will discuss; and the snake. These are considered forewarned even if they had never previously caused damage. Rabbi Elazar says: When these animals are domesticated they are not considered forewarned. But the snake is always considered forewarned. What is the difference between the liability incurred for damage caused by an ox that is considered innocuous and the liability incurred for damage caused by an ox that is forewarned? The only differences are that for damage caused by an innocuous ox, the owner pays half the cost of the damage exclusively from proceeds of the sale of the body of the ox, and for a forewarned ox he pays the full cost of the damage from his higher property.

חֲמִשָּׁה תַמִּין וַחֲמִשָּׁה מוּעָדִין, הַבְּהֵמָה אֵינָהּ מוּעֶדֶת לֹא לִגַּח וְלֹא לִגֹּף וְלֹא לִשֹּׁךְ וְלֹא לִרְבֹּץ וְלֹא לִבְעֹט. הַשֵּׁן מוּעֶדֶת לֶאֱכֹל אֶת הָרָאוּי לָהּ, הָרֶגֶל מוּעֶדֶת לְשַׁבֵּר בְּדֶרֶךְ הִלּוּכָהּ, וְשׁוֹר הַמּוּעָד, וְשׁוֹר הַמַּזִּיק בִּרְשׁוּת הַנִּזָּק, וְהָאָדָם. הַזְּאֵב וְהָאֲרִי וְהַדֹּב וְהַנָּמֵר וְהַבַּרְדְּלָס וְהַנָּחָשׁ, הֲרֵי אֵלּוּ מוּעָדִין. רַבִּי אֱלִיעֶזֶר אוֹמֵר, בִּזְמַן שֶׁהֵן בְּנֵי תַרְבּוּת, אֵינָן מוּעָדִין. וְהַנָּחָשׁ מוּעָד לְעוֹלָם. מַה בֵּין תָּם לְמוּעָד. אֶלָּא שֶׁהַתָּם מְשַׁלֵּם חֲצִי נֶזֶק מִגּוּפוֹ, וּמוּעָד מְשַׁלֵּם נֶזֶק שָׁלֵם מִן הָעֲלִיָּה: