is he an important figure in any other religion?
Yes, Judaism
Jonah
In Judaism, the story of Jonah represents the teaching of "teshuva", which is the ability to repent and be forgiven by God.
who gets swallowed by a whale in the bible Jonah
wiki:7770758
Jonah [SEP] Introduction
God shields Jonah from the sun with a plant, but later sends a worm to cause it to wither. When Jonah complains of the bitter heat, God rebukes him. In Judaism, the story of Jonah represents the teaching of "teshuva", which is the ability to repent and be forgiven by God. In the New Testament, Jesus calls himself "greater than Jonah" and promises the Pharisees "the sign of Jonah", which is his resurrection. Early Christian interpreters viewed Jonah as a type for Jesus. Jonah is regarded as a prophet in Islam and the biblical narrative of Jonah is repeated, with a few notable differences, in the Quran.