Rav Mutzafi on the Symbolism of Had Gadya
Rav Mutzafi has a video (in Hebrew), where the first 30 minutes of it explain 4 different explanations for the symbolism of Had Gadya.
He quotes the Gr"a, the Hatam Sofer, Rav Yaakov Emden, and Rav Yonatan Eybeshutz.
The 4 explanations start off:
1) Gr"a: Had Gadya + Had Gadya (we say it twice) = 2 kids that were used by Yaakov Avinu to get the blessings from Yitzhak Avinu (which by tradition occurred on the night of Pesah). This caused anti-semitism in the world, which sparks the rest of the events.
2) Hata"m Sofer: The Gadya is Korban Pesah and the rest of the events describe what occurs to the Korban.
3) Rav Yaakov Emden: The Gadya is the Neshama that is being bombarded constantly by the Yetzer Hara
4) Rav Yonatan Eybeshutz: The Gadya is Yosef Hatzadik who was sold by his brothers.
Note that according to opinions 1 and 4, the "Tora" (ox) is Rome and the "Shohet" is MBY.
Watch it here.