Nunca. Never have I had one come into play in a game. The giant shrew always reminds me of its scarier 1st edition cousin. Unlike the Brain Mole however, the shrew isn't psionic. It's big (for a shrew), but that only means it's about a foot long.
Shrew, Giant (from Moldvay)
Move: 180' (60')
Att: 2 (bites)
No. App: 1-4 (1-8)
What's wild about the giant shrew is that it's fierce! It's got a morale of ten! Which is feisty for such a little critter. It's only 1HD and has so-so AC, but it can jump 5' (neat trick for a rat-sized animal). It also can operate in complete darkness (echolocation).
Another wacky thing is it is fast. It automatically gains initiative for the first round, and gets +1 to the second rounds' rolls. Put a lair of them in a dark enough spot that they get a surprise round, and you might have up to eight of these suckers jumping out and getting a total of 32 attacks before the party even gets to act! (Eight shrews, 2 attacks each, surprise round + initiative in round 1). With that +1, there's a decent chance of them going first on the following round too!
The final amusing tidbit for the GS is where the book describes its attack as so vicious that 3HD or less creatures must Save vs. Death or flee in fear.
I am picturing this as a highly amusing low-level encounter that can leave the player wondering what exactly just happened to them.