Thunder Cocktail is a brandy-and-egg-yolk drink sharpened with cayenne pepper.
Harry of Ciro's ABC of Mixing Cocktails by Harry of Ciro's (1923, p.84) — Harry of Ciro's 1923
| 1 glass | brandy | base |
| 1 teaspoonful | Gomme syrup — Gomme Syrup | base |
| cayenne pepper — Cayenne Pepper | other | |
| 1 yolk | egg yolk | other |
This matters because it preserves a peppered restorative egg-and-brandy branch in the late 1923 seam.
Barflies and Cocktails by Harry McElhone and Wynn (1927, p.79) — Barflies 1927
| 1 glass | brandy | base |
| 1 teaspoonful | Gomme syrup — Gomme Syrup | base |
| cayenne pepper — Cayenne Pepper | other | |
| 1 yolk | egg yolk — Yolk of Egg | other |
This matters because it keeps the spicy yolk restorative edge visible inside McElhone's cocktail canon.
See also: Sherry Flip, Prairie Oyster Cocktail