In addition to the Pokémon listed below, Legendary Pokémon, Ultra Beasts, Pokémon encountered with Island Scan, and Pokémon encountered in the Ultra Space Wilds cannot call for help.
Note that Metapod, Bisharp, Oranguru, Passimian, and Jangmo-o can call for help. However, they cannot call their own species.
Butterfree
Poliwrath
Gengar
Electrode
Exeggutor
Starmie
Mr. Mime
Jynx
Snorlax
Dragonite
Crobat
Sudowoodo
Politoed
Espeon
Umbreon
Slowking
Octillery
Blissey
Sableye
Castform
Huntail
Gorebyss
Salamence
Ambipom
Happiny
Gabite
Lucario
(Blue-Striped) Basculin
Vanillite
Vanillish
Vanilluxe
Pawniard
Volcarona
(Orange Flower) Floette
(Blue Flower) Floette
(White Flower) Floette
Pangoro
Goomy
Sliggoo
Toucannon
Vikavolt
Mareanie
Wimpod
Minior
Komala
Kommo-o
Source: Bulbapedia
