Fenno was a hefty male shrew of the Guosim tribe. He bullied Dippler because it was the younger shrew's fault that all the logboats were stolen by Marlfoxes. The Log-a-Log was protective of Dippler, though, and insulted, threatened and hit Fenno whenever he abused the young shrew; as a result, Fenno became very resentful of Log-a-Log's authority. Things came to a head when Fenno voiced his disinclination to defend Redwall Abbey from the Marlfoxes, not wanting the Guosim to be "killed for creatures that ain't even shrews!" Log-a-Log planned to duel it out with Fenno after the battle with the Marlfoxes ended; this, however, never came to pass.