Chikorita can't be caught in dreamworld. It's DW ability isn't even released yet. They haven't made an event about Chikorita, or its evolution's yet, and Chikorita or its evolutions are not available in the Dreamworld. So we will just have to wait until it gets released. If you ever happen to get a chikorita with its dreamworld ability in a trade before it has been released, then you know for sure that it has been hacked, thus making it incompatible in wifi-battles that don't happen in the wifi-room.