[2] The assassin snail is found throughout southeast Asia, especially in Malaysia, Thailand, and in Lake Toba on the Indonesian island Sumatra.

[3][4] The assassin snail typically grows to 0.7–1.25 in (18–32 mm) in size, though this is dependent on food sources; they are usually smaller when kept in an aquarium.

The female lays several clear egg capsules which are square in shape and approximately 1.0 to 1.5 mm (0.039 to 0.059 in) in width and height.

[5] Like many snail species, Anentome helena can serve as an intermediate host to trematode parasites.

It has been confirmed as an intermediate host to Echinostoma revolutum in the Chiang Mai province in Thailand.