The index created by the World Wide Web Wanderer was called Wandex.
The World Wide Web Wanderer was a Perl-based web crawler developed by Matthew Gray at the Massachusetts Institute of Technology. It was first deployed in June 1993, when the web was still small enough that researchers were trying to measure its size and growth directly.
The Wanderer crawled the web and generated an index known as Wandex later in 1993. That made it an important precursor to search engines, although its original purpose was primarily measurement rather than serving as a general-purpose search service. The project tracked the web's expansion until late 1995.
The Wanderer is often described as probably the first web robot, but that label should not be confused with being a fully developed search engine. Its creator did not claim that it was intended as one. The other options in this question refer to unrelated search technologies: BackRub was Google's early name, Scooter was associated with AltaVista's crawler, and Architext was the technology behind Excite.