The Arachnobot has only one attack, but as it's an area attack, it is nearly impossible to not get damaged by it. Joining the Arachnobot is its four Arachnolings who all have Rake, Lateral (1) and Slime, which allows them to trail damaging slime around them. Despite this, they are all level 1 and can't really do much in the damage department when compared to the Arachnobot. However, the Arachnobot, will create four more Arachnolings with the words, "Hatchlings spawned" every couple of turns. As that is the case, it is best to try and deal with the Arachnobot first as any Arachnolings left after the Arachnobot's death will automatically perish as well.