He was sad that all the other grues ate his babies. So he set upon an epic quest to Never-Neverland to start his own site where everyone would be his friend. Along the way he met may fictional characters, including but not restricted to dragons, world leaders and miscellaneous anthropomorphic beings - the latter in particular of which he would later come to make a famous documenthairy.
When he finally reached his new home in Never-Neverland he instantly came across a wild Michael Jackson and they partied together. The Grue Named Tom especially liked it when Thriller came on, as light up paving tiles made his face light up with undeniable happiness.
However he ended up meeting a hobbit named Frodo. Then he died of Blaintralexus, desperate attempts to cure it through rigorous applications of Texas Chainsaw Manicures having proven unsuccessful despite the assistance of highly skilled fishy moose-ickians.