



Lensa, Sassilik and Freygerd are all NPCs on Rellekka, but are also on Jatizso. They share the same names and appearances, but only slightly different examines of "One of Rellekka's/Jatizso's many citizens".
Along with this, they reused Sigli the Huntsman, for an armour seller in Jatizso too. As far as I know, this is the only time I've seen a quest NPC be used twice.
I originally found this on RS3, but noticed that it is still the same in OSRS.
However interestingly, in RS3, the gate guards for Jatizso are called 'Leftie' and 'Rightie', who joke about left and rights. These are also duplicated in the northern parts of the land, and are fighting trolls, where you can talk to them and ask them to let you through the gate, even though you're by the trolls (no where near Jatizso).
In RS3, you can talk to the guards to find this bug, but oddly enough in OSRS, the guards don't have any talk options.