Taken from a Gamefaqs Guide
http://www.gamefaqs.com/n64/196973-conkers-bad-fur-day/faqs/...I had it open in a tab from earlier tonight lol
OK, let's kick some alien ass. Punch it a few times to knock it down, then run
around and grab the tail. Now, who hasn't played Super Mario 64? Spin your
control stick faster and faster until the alien isn't scraping the floor and
toss it through the airlock. Do this three times to defeat it. After the first
one, you'll have to watch out. It will start spinning around, and it won't let
you punch it. When it looks like it's about to spin, jump and hang in there
until he does it. It bites, too. When it tries, hit Z to block, then whale on
it with B. The third time it lunges a lot, so it should be easy to stun him.
Hitting him is another story. When you DO get him out the third time...