You might be looking for Nachman bar Huna or Nachman bar Yaakov.

Rav Nachman bar Yitzchak or Rabh Naħman bar Yişħaq in actual Talmudic and Classical Hebrew (died 356) was an amora

Amora

Amoraim , were renowned Jewish scholars who "said" or "told over" the teachings of the Oral law, from about 200 to 500 CE in Babylonia and the Land of Israel. Their legal discussions and debates were eventually codified in the Gemara...

 (rabbi of the Talmud

Talmud

The Talmud is a central text of mainstream Judaism. It takes the form of a record of rabbinic discussions pertaining to Jewish law, ethics, philosophy, customs and history....

) who lived in Babylonia. He was a disciple of Abaye

Abaye

Abaye was a rabbi of the Jewish Talmud who lived in Babylonia [בבל], known as an amora [אמורא] born about the close of the third century; died 339 . His father, Kaylil, was the brother of Rabbah bar Nachmani, a teacher at the Academy of Pumbedita. Abaye's real name was Nachmani, after his...

 and Rava

Rava

Rava may refer to:* Bishnuprasad Rabha* Abba ben Joseph bar Ḥama , a Jewish Talmudist who lived in Babylonia, always known by the honourific name Raba/Rava* Rava , an island in the Croatian part of the Adriatic sea...

 and the dean of the yeshiva

Yeshiva

Yeshiva is a Jewish educational institution that focuses on the study of traditional religious texts, primarily the Talmud and Torah study. Study is usually done through daily shiurim and in study pairs called chavrutas...

 at Pumbedita

Pumbedita

Pumbedita was the name of a city in ancient Babylonia close to the modern-day city of Fallujah....

.

In his youth, Rav Nachman studied together with Rava

Rava

Rava may refer to:* Bishnuprasad Rabha* Abba ben Joseph bar Ḥama , a Jewish Talmudist who lived in Babylonia, always known by the honourific name Raba/Rava* Rava , an island in the Croatian part of the Adriatic sea...

, but he sat one row behind him. Later Rav Nachman studied under Rav Chisda

Rav Chisda

Rav Chisda was a Jewish Talmudist who lived in Babylonia, known as an amora of the third generation , mentioned frequently in the Talmud.-Youth:...

. During the time when Rav Joseph bar Chiya was head of the Yeshivah of Pumbeditha and Rava conducted his own Yeshivah in Mechoza, Rav Nachman bar Yitzchak was the chief lecturer (Resh Kalah) under Rava, and he was already famous for his great learning and piety.

Legend states that a soothsayer predicted to Nachman's mother that her son would be a thief. She was therefore very careful to instill in him a fear of heaven. She often reminded him: "My son, cover your head completely, so that you will fear G-d, and always pray for his mercy, so that you should not be overcome by your evil impulses". It is told that once while studying under a tree, his headcovering slipped off, and he suddenly felt a tremendous desire to take a cluster of dates from the tree (which did not belong to him). (Shabbos 156b)

He praised the character trait

Character orientation

Character orientation is how people relate to the world by acquiring and using things and by relating to self and others , and they can do so either nonproductively or productively....

 of humility greatly. His modesty may be seen from the fact that when Rava stated that "a little pride is becoming a scholar," Rav Nachman hastened to remark, "None of it, nor part of it!"

He worked to facilitate a peaceful relationship between husband and wife

Marriage

Marriage is a social union or legal contract between people that creates kinship. It is an institution in which interpersonal relationships, usually intimate and sexual, are acknowledged in a variety of ways, depending on the culture or subculture in which it is found...

.

The honour of the Sabbath was of prime importance to him. He would even personally do menial chores in its honour. He would say that "one who honours the Sabbath will be saved from the pains of the exile".

He had a quick wit often using the double entendres as a pmnemonic device.

It is unclear which of the three sages called Nachman are referred to when R' Nachman w/o a surname is mentioned. However, the fact that Rav Nachman bar Yitzchak often states a position after R' Nachman (w/o surname) should allow us to rule him out. (Tosafot to Tractate Chullin)

Two interesting statements

Rav Nachman bar Yitzchak stated in Berakhot

Berakhot (Talmud)

Berachot is the first tractate of Seder Zeraim, a collection of the Mishnah that primarily deals with laws relating to plants and farming...

 11a, "One who acts according to Bet Shammai, deserves death". This is in contrast to Rav Yehezkel who says "One who acts according to Bet Shammai, has acted [i.e., has fulfilled one's obligation]" and Rav Yosef who says, "One who acts according to Bet Shammai has done nothing."

Rav Nachman is also reported to have stated (in Nazir

Nazir (Talmud)

Nazir is a treatise of the Mishnah and the Tosefta and in both Talmuds, devoted chiefly to a discussion of the laws of the Nazirite laid down in Numbers 6:1-21. In the Tosefta its title is Nezirut...

 23b and Horayot

Horayot

Horayot is the final tractate of Seder Nezikin in the Talmud. It discusses laws pertaining to errors in judgment by a Jewish court....

10b), "Greater is a sin for the sake of Heaven than the fulfillment of a precept that is not for the sake of heaven". This statement is seen as a justification for the actions of Lot's daughters who had sex with Lot to maintain humanity (Genesis 19), Tamar who pretended to be a prostitute to establish the line of her late husband (Genesis 38), and Yael who, according to the rabbis had sex with Sisera before killing him (Judges 4-5).