This has probably been reported before, but I can't find it anywhere so here 'tis.
I modded my megabeasts to help them survive worldgen, and in the process I gave Titans (among other things) buildingdestroyer 2:
[CREATURE:TITAN]
[NAME:titan:titans:titan]
[TILE:'T'][COLOR:3:0:0]
[MEGABEAST]
[GENPOWER:5]
[FANCIFUL]
[CAN_LEARN][CAN_SPEAK]
[CANOPENDOORS]
[PREFSTRING:height]
[BODY:HUMANOID:2EYES:2EARS:NOSE:2LUNGS:HEART:GUTS:ORGANS:HUMANOID_JOINTS:THROAT:NECK:SPINE:BRAIN:5FINGERS:5TOES:MOUTH]
[SIZE:90]
[ATTACK:MAIN:BYTYPE:GRASP:punch:punches:8:16:BLUDGEON][ATTACKFLAG_WITH]
[ATTACK:SECOND:BYTYPE:MOUTH:bite:bites:8:16:GORE][ATTACKFLAG_CANLATCH]
[CHILD:12][BABY:1][MULTIPLE_LITTER_RARE]
[FAT:20]
[EQUIPS]
[DIURNAL]
[BIOME:ANY_LAND]
[STANDARD_FLESH]
[HOMEOTHERM:10067]
[LAYERING:10]
[SWIMS_LEARNED][SWIM_SPEED:2500]
[SPHERE:LONGEVITY]
[SPHERE:WISDOM]
[DAMBLOCK:200]
[NOFEAR]
[NOPAIN]
[POWER]
[STOUT]
[BUILDINGDESTROYER:2]
Fast forward a bit, and in the fifth year of my fortress I get a surprise visit from the eminent Lulo Focusedyears the Ancient Lens, Titan. I activate my defenses and watch as she approaches the entrance to my fort, stopping only to destroy a farm plot that is one z-level down through a natural clay floor:
The hot pink area is where the farm used to be. Note that she's one z-level above AND one tile north of the plot.
Except for modded megabeasts and Rantingrodent's graphics pack, my game is vanilla d16. It's not anything terribly bad, really. I assume it's somehow related to pathing; the Titan still needed to be adjacent to (though one z-level above) the plot. So has anyone else seen this?