Those coming from Linux® are often surprised to find that Bash is not the default shell in FreeBSD. In fact, Bash is not even in the default installation. Instead, FreeBSD uses tcsh(1) as the default shell. Although, Bash and your other favorite shells are available in FreeBSD's Packages and Ports Collection.
If you do install other shells you can use chsh(1) to set a user's default shell. It is, however, recommended that the root's default shell remain unchanged. The reason for this is that shells not included in the base distribution are normally installed in /usr/local/bin or /usr/bin. In the event of a problem the file systems where /usr/local/bin and /usr/bin are located may not be mounted. In this case root would not have access to its default shell, preventing root from logging in. For this reason a second root account, the toor account, was created for use with non-default shells. See the security FAQ for information regarding the toor account.