Snarf Osbert (or just "Snarf") is of the Snarf species and was Lion-O's nurse-maid as a child (and as an adult much to Lion-O's chagrin). His nephew Snarfer calls him "Uncle Osbert."
Entrusted with the care of the young Lion-O, Snarf Osbert (known simply as "Snarf" to his fellow ThunderCats) often thinks of himself as the oldest member of the group. Although Snarf is an excessive worrier and something of a pessimist, his courage and loyalty is as evident as any full-sized ThunderCats, particularly when defending Lion-O.
At the start of the series, Snarf was often complaing how he is ignored by the others, as well as having to nothing important to do now that the young lord Lion-O has grown into an adult. But as the series goes on, Snarf proved to be just as much of a ThunderCat as the others.
He is also more understanding than most of the other Thundercats, as he once pointed out to the ThunderCats how wrong it was for them to be angry with Kit and Kat after they confessed releasing Mongor by mistake.
