CL-USER> (defclass foo () ())
#<STANDARD-CLASS COMMON-LISP-USER::FOO>
CL-USER> (defclass bar () ())
#<STANDARD-CLASS COMMON-LISP-USER::BAR>
CL-USER> (defvar *foo-class* (find-class 'foo))
*FOO-CLASS*
CL-USER> (defvar *bar-class* (find-class 'bar))
*BAR-CLASS*
CL-USER> (eq *foo-class* (find-class 'foo))
T
CL-USER> (setf (class-name *bar-class*) 'foo)
FOO
CL-USER> (eq *foo-class* (find-class 'foo))
T
CL-USER> (find-class 'bar)
#<STANDARD-CLASS COMMON-LISP-USER::FOO {1003B32833}>
CL-USER> (eq *bar-class* (find-class 'bar))
T
CL-USER> (class-name *bar-class*)
FOO
CL-USER>