Mummy (Dungeons and Dragons) vs Gambit: who would win?

Gambit favored — Slight edge (~55%)

Mummy (Dungeons and Dragons) · Dungeons & Dragons · Mummy Lord

Tier
LOW 7-B, up to 6-C
Attack Potency
Small City Level, up to Island Level+
Speed
Hypersonic+, up to High Hypersonic+
Durability
Small City Level, up to Island Level+

Gambit · Marvel · Horseman of Death

Tier
LOW 7-B
Attack Potency
Small City Level
Speed
Sub-Relativistic+
Durability
Small City Level

A heuristic estimate from normalized VS Battles Wiki stats: tier, attack potency, speed and durability.