The Star Beast

Lummox has been the pet of the Stuart family for generations. With eight legs, a thick hide and huge (and growing) size, Lummox is nobody's idea of man's best friend. Nevertheless, John Stuart XI, descendant of the starman who originally brought Lummox back to Earth, loves him. But when Lummox eats a neighbor's car and begins to grow again, the Feds decide enough is enough. John isn't about to let the authorities take his pet away, and with his best friend friend Betty, determines to save Lummox even if it takes leaving the life he's known forever.
An all time science fiction coming-of-age classic from seven-time Hugo winner and Dean of Science Fiction, Robert A. Heinlein.
About Robert A. Heinlein:
Not only America's premier writer of speculative fiction, but the great writer of such fiction in the world. '“Stephen King.
One of the grand masters of science fiction. '“Wall Street Journal