See, according to the Spongebob wiki, his Mandarin name is Hǎimián Bǎobǎo, while his Cantonese name is Hóimìhn Bóubóu. I thought it sounded more like the latter, but it might just be Patrick's simpleton voice making it sound different. Or it might just be that I'm still woefully unlearned. I'd guess it's a combination of the two.