Ha ha! His are big shoes to fill!
Unless one is into writing, 300-400 words should cover everything - where you're from, how you got your username (always a nice ice breaker), your hobbies and interests, likes and dislike (try to make it fun), how you found out about Hive, links to personal websites and social media (if they plan to cross post get them to add a Hive link there so we know they're not an imposter), crypto experience (if any), and what you're hoping to get out from Hive. And if they not anon, a selfie holding a Hive logo and date to verify identity will be ideal. It adds creditability.
Wow! Thanks a lot for this guideline! You're awesome! I'll add this to the intro guideline sheets.