Fred was born on some planet somewhere (no, what was your first clue sherlock?) in 2511 and was almost not chosen for Some crack heads experearmints program on account of him looking so normal. He was however, chosen in 2517. In 2519, when the trainees began learning self defense, Fred ended up 'accidentally' kicking CPO Mendez in the face, breaking his nose. John (again, he's the Master Chief, n00b!) was impressed and the two became friends, although John realized that Fred looked way too normal to be a SPARTAN. Even after augmentation, Fred could easily blend into a crowd, even though he was now a 7 foot tall super human badass with grey streaks in his hair. Fred was simply too normal looking. He later distinguished himself by becoming the SPARTAN's best hand-to-hand combat expert, and an expert with bladed weapons such as combat knives (although this has lead to several awkward moments as referenced by Kelly). He later pwned innies with his skillz in 2525 and went on to kill jankloads of Covenant on over 200 missions. He fought on Reach and later, along with Kelly and Linda, found out the hard way that Onyx really is made of sentinels. He and the other SPARTANs escaped into Onyx's core.
Fred is the most normal (too normal in fact) of the SPARTANs, which is one reason why not much is written in the above section. The other being that the flaming ninjas seem to have forgotten him. This has lead to him being picked on by many other SPARTANs, John included. However, he is an expert in hand-to-hand combat. If you piss him off, he can and will kick your @$$. He also owns a splazer, and if he feels lazy, will simply vaporize you with it. And if that doesn't work, he also carries a shotgun with a bayonet duck taped to the barrel (he seems to use sharp, pointy weapons a lot. no, not like that. GET YOUR MIND OUT OF THE GUTTER N00B!!!).