It may be BS, but he didn’t make it up.
1) We have two stories preserved in supplements to the Mishnah called the Tosefta (as well as in other parallel rabbinic texts but primarily see Tosefta Chullin 2:22-24) that refer to “Yeshu ben Pantera” (with alternate spelling variations). The first involves the famous Rabbi Eliezer ben Hyrcanus who lived in the late 1st and early 2nd century AD. Rabbi Eliezer relates a teaching in the “name of Yeshu ben Pantera” that he heard on the streets of Sepphoris from one Jacob of Kefar Sikhnin. Eliezer himself had been arrested for “heresy” and some have suspected he might have been sympathetic to the Nazarenes. The second story also involves Jacob of Kefar Sikhnin who attempts to heal a certain Rabbi Eleazar ben Dama of a snakebite in the name of “Yeshu ben Pantera.”
Although Maier and a few others have doubted these references are to Jesus of Nazareth, most experts are convinced that they are. Since both of these texts appear to use the designation “Yeshu ben Pantera” in a descriptive rather than a slanderous or polemical way they offer us evidence that Jesus was remembered as “son of Panthera” in the region of Galilee, and even on the streets of Sepphoris, in the early 2nd century. Indeed, Richard Bauckham argues quite persuasively that this Jacob of Kefar Sikhnin might well be James, son (or grandson?) of Jude the brother of Jesus, otherwise known to us as a prominent leader in the Galilean churches (Jude and the Relatives of Jesus, pp. 114-119).
2. The Greek philosopher Celsus relates in polemical work against the Christians preserved by the Christian theologian Origen that he had found it “written” that Jesus was the son of a Roman soldier named Pantera (Contra Celsum 1. 69). This text dates to the late 2nd century. Origen replies that the story was concocted by those who refused to believe that Jesus had no human father and was conceived by the Holy Spirit.
3. The 4th century Christian apologist Epiphanius seems to take the designation “Jesus son of Panthera” seriously in that he argues the name is actually a nickname for Jacob, the father of Joseph, husband of Mary. So rather than denying it is part of the family tradition he tries to explain it within that context.
12When the chief priests had met with the elders and devised a plan, they gave the soldiers a large sum of money, 13telling them, "You are to say, 'His disciples came during the night and stole him away while we were asleep.' 14If this report gets to the governor, we will satisfy him and keep you out of trouble." 15So the soldiers took the money and did as they were instructed. And this story has been widely circulated among the Jews to this very day. - Matthew 28:12-15
I believe that more lies have been told about Jesus than have been told about any other person.