Slowpoke vs Sub-Zero Manta: who would win?

Sub-Zero Manta favored — Slight edge (~55%)

Slowpoke · Pokémon · Mainland/Galarian Slowbro/Slowking

Tier

6-C

Attack Potency

Island Level

Speed

Below Average Human, up to Ftl

Durability

Island Level

Sub-Zero Manta · Godzilla · Base

Tier

6-C

Attack Potency

Island Level

Speed

Subsonic, up to Supersonic+

Durability

Island Level

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