Dragon Quest Monsters: Joker 2 Hints for Nintendo DS
To obtain captain crow first go to the arena and talk to the mole by the blue chest he says something about Crow and you can beat him when it's raining in an area. He has a couple orcs or orges at first(which are really easy to kill if you have D rank or higher monsters) and time after time he'll get stronger and stronger. After you beat him 3 times talk to the mole again and he'll give you a whip captain crow will reappear again with A Marequis De Leon(I must admit this one is easy to but rank a monsters or higher should defeat it with ease). After that talk to the platypunk next to the mole in the arena he says Captain Crow is back again. This time he faces you alone and if you beat him he says he wants to join you. (I recommend making Dr Snapped with him don't use him to make Zoma though).
A Mimic is a useful monster because of it's trait. Its trait Pro Talent Scout increases recruiting chances. Problem is it's hard to recruit one. However it's not to hard to synthesis one. Just get a Golem and a Cannibox then synthesis them. Now easy way to get a Cnnibox is to synthesis two Goodybags and to get a Goodybag you can try to find one or synthesis two Bag O' laughs. Should be easy to synthesis a Bag O' laughs early in the bag. A Golem can be found later in the game at Bemusoleum though you may be able to synthesis one earlier. You might also be able to synthesis a Cannibox with another monster to get a Mimic so try matching it up with different monsters if you can't get a Golem.
If you want to try your hand at recruiting a Mimic then best place to go would be Necropolis.
Theres not much you can do to increase your monster scouting chance but there are a few things. Have a high level high ranked monster. Green Dragon X is good. There are also some monsters with traits that increase recruiting chance. Early in the game you can get monsters with the ability Talent Scout. These are Satyr and Conklave. Later in the game you can get a monster called a Mimic who has the ability Pro Talent Scout.
In the battle arena there is a room where if you helped the mud mannequin in Treepidation get it's heart you can do what I consider side quests. These side quests are called the Scout Proficiency Tests. Doing these quests give you several items. Two of these are the Plus and Minus sceptres. Give a monster you plan to synthesis the sceptre with what you want the offspring to be. Doing that should grantee that the monster you synthesis will always have the + or - depending on which one you were going for.
To get the Green Dragon X you need two level 20 Green dragons and synthesis them. This will give you a strong Rank B monster. You can also get a Chimaera X by synthesizing two Chimaera at level 20. The same goes for the following monsters, Conklave X, Goodybag X, Skeleton X, Slime X, Teeny Sanguini X. Just have two of their normal forms at level 20 before synthesizing.