Cross Poison
36 Alpha species can unlock this TM. Alphas know 2 random TM moves from their learnset — catching one of the Pokémon below that knows Cross Poison unlocks the recipe.
TM Machine recipe
Craft at a TM Machine with a Blank TM after the recipe is unlocked. Full Cross Poison TM guide
Alpha Pokémon that can unlock Cross Poison
These species include Cross Poison on their Cobblemon TM learnset, so an Alpha of that species can roll it. This is the accurate Cobblemon TM location for Alpha hunting — not a fixed drop table.