Although the giant mole is possibly the easiest boss in runescape, I'm going to give u guys tips on faster kills.
1.bring a poisoned weapon... A dds p++ Is advised... This will make sure that u do damage while it digs.
2.bring a summoning familiar. If u use a familiar to attack the mole, ur familiar will immediately turn in the direction that the mole has run to.
3.bring a few extra prayer potions, an extra summoning pouch, and a spade. (you also must bring a light source. I recommend a bullseye lantern, because it won't burn out.
I hope this helped u guys
<3