This was a recent hilarious moment. A cleric of Kossuth failed his save vs plane shift and found himself in a lush primordial jungle. In short order, he came across a T-Rex a-hunting.
The hungry Rex snapped the cleric up and scarfed him down (swallowed whole). Now the cleric was something like 13th level and had a potent arsenal of spells remaining but for whatever reason, he fixated on trying to cut himself out of the stomach. After taking several rounds of digesting damage, the cleric succeeded.
Now a T-Rex has a brain not much larger than a man's fist and is about a smart as a sack of hammers - see food, catch food, eat food is about as complex as it gets....
So the T-Rex, still hungry, spots the prone cleric at its feet and - snap, the cleric disappears down the gullet yet again. Again, for whatever reason, the cleric is fixated on cutting his way out. More digesting damage and once again, the cleric finally cuts his way out, only to...
Snap....swallow. Down the slippery gullet disappears the cleric a third time. The dumb Rex can't figure out why he is chowing down and not getting full. And the cleric is still having a dumb moment in not realizing that he has recourse to spells which would help immensely in dealing with the T-Rex.
Out pops the cleric. Down the hatch goes the cleric. By this time, the rest of the players are nearly wetting themselves with laughter, further frustrating the flustered player of the cleric.
On the FIFTH round trip down the gullet, the player in complete frustration mutters that he has made the trip down the gullet so many time, he has left graffiti on the inside surfaces of the Rex's teeth.
At this point, I can't take anymore.....my sides are hurting too much. I finally remind him that he is after all, a CLERIC and that maybe he should consider his spells as a solution to this problem. By this time, the cleric is very low on hit points.
The player of the cleric announces he is casting HEAL on himself. I can't believe it.

Simultaneously, three other players scream out...
'Use your HARM spell, dude!!!!' (note: this was prior to 3.5 coming out)
The player of the cleric sat red-faced and sheepish. He got ribbed for a good long time about that encounter. To this day, he doesn't know why he never considered using spells.
How many people can claim that they swallowed whole - 5 times - by the same monster.
