Green’s Dictionary of Slang

a non-specified but extremely large number.

1999		L. Gould Shagadelically Speaking 4: $1 kajillion bajillion, Figure the president of the United Sates mockingly suggests Dr. Evil might as well ask for when the latter demands a $100 billion payment.
2018		K. Stamper in Twitter 19 Nov. 🌐 Many of you know that I was a lexicographer at Merriam-Webster for a bajillion years.
2018		‘Aidan Truhen’ Price You Pay 249: I musta seen it [i.e. a restaurant] a bajillion times and never been in.
2022		J. Hannaham Didn’t Nobody Give a Shit 150: [U]nless you had a bajillion dollars and your face popped up on billboards [...] you weren’t a celebrity.