Grenade droids were a type of B1-series battle droid in the Separatist Droid Army. In 22 BBY, a number of grenadiers served as part of the assigned to defend the Separatist droid factory on Thule.
Grenade droids made their canon debut within the novel Inquisitor: Rise of the Red Blade by Delilah S. Dawson but had made prior appearances in Star Wars Legends. Dawson discovered the Legends incarnation of the grenadiers via Wookieepedia when researching if such a droid unit existed and decided to incorporate them into her novel. When asked by a fan if the grenade droids seen in her novel were a variant of the B1-series, she confirmed they were a canonization of the Legends B1 grenadier class.
Grenade droids made their canon debut within the novel Inquisitor: Rise of the Red Blade by Delilah S. Dawson but had made prior appearances in Star Wars Legends. Dawson discovered the Legends incarnation of the grenadiers via Wookieepedia when researching if such a droid unit existed and decided to incorporate them into her novel. When asked by a fan if the grenade droids seen in her novel were a variant of the B1-series, she confirmed they were a canonization of the Legends B1 grenadier class.