In 1996, he gained his first significant exposure, when he was 10 years old, when he played Mowgli, the main role in the musical "The Jungle Book", alongside Tuvia Tzafir and Hanoch Rosen.

[1] In the following years, Avni participated in the musicals "King of Siam" (2000), "Tiny" (2002), "Tom Sawyer and Huckleberry Finn" (2003) and "Aladdin" (2004).

In 1997, he starred and hosted Festigal, and even came in second place in the competition with the song "Luna Park", which he performed together with Nalia Tzachman.

In 2007, a mockumentary program that followed his life called "24/7 - Tom Avni" aired on the children's channel Hot 3.

In 2011, he played the role of Bini Meltzer, the poster boy of the Har Tzur yeshiva, in the drama series of Yes, "Urim VeTumim [he]".

[15] In 2020, he played Captain Tamir, an officer in the blacksmith camp, in the series Valley of Tears that aired on Kan 11.

[15] In 2023, the series "The Malevolent Bride [he]" was broadcast on Kan 11, in which Avni played the character of the physicist Dov Baer.