The sigil of the Alpha Legion
A Venom Sphere was a specialised assault grenade utilised only by the Alpha Legion during the Great Crusade and Horus Heresy eras of the late 30th and early 31st Millennia.
This deadly weapons upgrade replaced the more commonplace anti-personnel Frag Grenades employed by the other Space Marine Legions for advanced variants which contained toxin-impregnated crystalline splinters that have been darkly claimed to be based on xenos technology. It is unknown if these weapons are still deployed by the Alpha Legion in the late 41st Millennium.
Sources[]
- The Horus Heresy Book Three - Extermination (Forge World Series) by Alan Bligh, pg. 259