The best passives for Jormuntide depend on the job you give it. Jormuntide is Paldeck #121, a Dragon / Water Pal with Watering 7 — the sets below are the community-consensus best-in-slot for each role it can fill.

LegendDemon GodMuscleheadDivine Dragon
Legend, Demon God and Musclehead stack raw attack; Divine Dragon adds 20% Dragon damage on top.
ArtisanSeriousLuckyWork Slave
Maximum work speed. Work Slave trades attack a base worker never uses; swap for Nocturnal on day-sleepers if sanity drops.
SwiftRunnerNimbleLegend
Every movement-speed passive stacks; Legend adds 15% more plus combat stats.
A perfect Jormuntide also wants 100/100/100 IVs (breeding averages the parents with a bonus, so high-IV Jormuntide parents compound) and 4-star condensation — feeding it spare copies raises this Dragon / Water Pal's stats and every work suitability a full level. Craft-speed and attack souls from the Statue of Power stack on top. The planner routes these passives from pals you own; see how to breed Jormuntide for parent combos.
Breed this Jormuntide build from your save →