• Mobile Googlebot- A robot indexing sites for mobile devices and wap communications.
• Google Search Appliance (Google) gsa-crawler – search engine robot for new hardware-software systems is call Google Search Appliance,
• Googlebot-Image – robot crawls pages for its main image index,
• Mediapartners-Google – robots crawl pages to determine AdSense service,
• Adsbot-Google – bot scanning for assessing the quality of landing pages by its AdWords service.
There is a theory of the sandbox effect, which states that sites that have new domain names, the frequent change of owners or name servers place them in the sandbox (holding area) and they remain there until a specific mechanism by Google, these criterias have already been created to meet the quality standards of websites and copyrights, etc is done to avoid the fraudulent activities by some new websites.
Also there is an inverse theory called “Bonus” in which the initial indexing of your site gets boosted by Google itself, because of certain aspects (such as several links to authoritative sources), site immediately assigned a high Page Rank and good places in the SERP. I’ve yet to experience this myself, but you never know, it could happen.