You could try Clarendon for one.

You mean like a slab serif -- Memphis or something like that?

Biggest serifs I know of were in 1960s San Francisco psychedelic poster lettering.

Nothing like Bodoni or Waters though.

Are these serifs big enough?

Tom thats a riot!

When I read your question I wasn't thinking about thick serifs, I was thinking thin and long. My suggestions are Carol Twombly's 'Charlemagne', or Xavier Dupre's new one for Font Font called 'Angkoon'

You could also look at Ablefont. I can't find a showing for this but when I googled it I learned that it was used for Harry Potter. It's a variation on Charlemagne but less regular.

I know a typeface with such long serifs the designer had to bend
them inwards in order to make the characters fit next to each other.