The term "Tachyon Spider Bot" is conjectural. The real name is unknown, and a non-canonical nickname or title is used instead. See the reasons for this title in the "Behind the scenes" section below and/or the relevant discussion on the talk page, if there are any.
Tachyon Spider bots were small robots, resembling spiders, that Tachyon deployed in both stages of the battle, they would come up to Ratchet and blow up. The only strategy is to use a secondary weapon such as the Nano Swarmers or Mr. Zurkon.