So.. i got a dagganoth task and i've never fought a daggonoth besides the boss in horror from the deep. I heard they were the best slayer xp when using cannon so i didnt wanna skip it.So what should i do?

Dagannoths under the lighthouse.Take 1-2 super sets and barrows body/legs(torag/guthan/dharok) will be just fine. Also take either a buny and 20 or so scrolls or just a buny and a few pieces of food.

For fast slayer xp (yet somewhat costly) you can connon them under the lighthouse.

 

 

 

The dagganoths in the choas tunnels are my favorites (better drops) but they cannot be cannoned.

Cannon them in the lighthouse. 3 or 4 pieces of food should be more than enough, so a healing familiar isn't reall necessary. Most of their drops stack (charms/seeds) so a beast of burden isn't really worth it either. That leaves your best combat familiar, but the task will be over so fast I don't think it's worth wasting the summoning points =P

Chaos Tunnel ones have better drops and have more HP so more experience, you'll need prayer potions but with the drops you will easily make a return. The lighthouse ones are very quick and easy, although you won't get as much money or experience.

Chaos tunnel ones usually profit, ande are not all that much slower.

Lighthouse ones barely need food. I'd take food, barrows and whatever familiar you use to get all things to attack you.