The later, more popular versions of the BSD daemon were drawn by animation director John Lasseter beginning with an early greyscale drawing on the cover of the Unix System Manager's Manual published in 1984 by USENIX for 4.2BSD.
Marshall Kirk McKusick, then a Berkeley graduate student, optimized the BSD 4.2's FFS (Fast File System) by inventing cylinder groups, which break the disk up into smaller chunks, with each group having its own inodes and data blocks.