I used Smeargle. Zoroark is in the same egg group as Smeargle so if you sketch Dark Pulse and Memento onto Smeargle you can get both. Make sure it's a male Smeargle though obviously.
Dark Pulse shouldn't be too hard to Sketch, but Memento is trickier because the pokemon that uses it will faint before you can sketch it. The best way to do it is to obtain two pokemon with Memento (just catch 2 Litwick and level them up a bit until they learn it). Smeargle must be faster than the slowest of your 2 Memento users. Send your 2 Memento pokemon out into a wild double battle and have them use Memento on each other. The faster Memento user will use the move and faint but the slower one will try to use it and fail because there is no longer a target! Then, simply send out Smeargle and have it use Sketch on the remaining Memento pokemon. You should now have a Smeargle with Memento!