im trying to get the Dragon hatchlings and iv heard of a stratagy where you can get a monster which has the ability to escape a battle straight away.
A monster called metallo can be caught in the ruins south of lassandal 
It evolves into metallodious that can escape in battle 
It can be found on any floor of the ruins beneath lassandal.try to get 2 as one unevolved one is needed to make barricadus and another evolved version of it can use the escape ability to farm for rare arks quickly
Hope this helped your quest for dragons 
thats great, iv got my metallodious now and its so much quicker! iv heard it can take a long time to get a hatchling so this method should hopfully speed things up, when i finally find one, will a gold capture card do?
Nah for me (completed the game) it is a 97% chance to capture with my second best card
The gold card is not necessary though but if you don’t want to risk it then use gold because I’ve heard of people missing stuff with 90+% capture rate
I have missed twice on a 97% capture rate 
damn you to hell leafy! All good though twenty minutes later found him again and caught him! Only an e class though
If you are having trouble with the catch percentages, use a weak monster with Plague to deal a small amount of damage and boost the chance to 100%. I use a level 6 Puffor and it gives me 100% catch chance after it uses Plague.
Are you sure? Farming for hours… One becomes awfully paranoid to attack and risk one shotting a hatchling
A level 6 Puffor does approximately 180 damage over 500 TU. It usually takes about 1/4 to a 1/3 off the total health of a hatchling if you use it right before it attacks. All you need is that little bit of extra damage to bump the catch % up to 100.