Slimer's evil twin Achievement
Slimer's evil twin20
Kill the Solar boss in an online game session.
There is one level to do this on: Ribbit IV. Solar bosses are the fat frogs in on the left and right areas in the center jungle area (they are near large health drops). These guys are tough, and I don't recommend taking one down until you have a bunch of upgrades. You need to land the killing blow for credit. This must be done online private or public.