Oreo Competitor That Actually Predates Oreo

This page is the CodyCross answer for the clue below from House of Horrors, Group 1104, Puzzle 2 (Creepy Children).

Question is: Oreo Competitor That Actually Predates Oreo

and the answer is: HYDROX

Word Meaning:

HYDROX — A breathing gas composed of hydrogen and oxygen used for its lighter weight than air.

Definitions from Wiktionary.