Roflconda is a large, snake-like creature consisted of many Creeper heads. The name is likely attributable to the horrifying, troll-like nature of the beast. Like its relative, the Creeper, it explodes when close to its prey. Combined with it's extreme speed and unsettling appearance, however, first-time encounters may be much more hilarious to watch (hence the warning.)
One key difference from the Creeper, however, is that several ligaments of the Roflconda explode at once; while each explosion is smaller than the Creeper's one, their combined power is much more devastating. Similar to the Creeper, striking the Roflconda with lightning may result in extreme fun.
A notable feature of the Roflconda is that it only takes damage when struck in the frontmost head. Thus, consistently knocking one out of explosion range requires timing and skill (especially when using a ranged weapon.) It is unclear if this is an intentional feature. Nonetheless, the Roflconda's anterior heads will push the player away if he's standing near them.
Individual Roflconda explosions aren't powerful enough to one-shot a Mage of similar level. Multiple Roflcondas, however, can pwn you, so be careful.
Like the Creeper, the Roflconda will become "supercharged" when struck by lightning, doubling the power of its explosion. Since rare spawn Creepers and Roflcondas already have double the base explosive power, supercharging one will result in quadruple the fun...
Because of dirt's temporary role as a repair reagent and it's low resistance to explosions, it can be beneficial to have a Creeper or Roflconda explode near you, using the ensuing rubble to replenish your gear.
For some reason, the normal creeper (and to a lesser extent, Phase Creepers) can sometimes be quite rare. But the Roflconda seems to be all over the spawn rate in quite a lot of worlds. I have no idea what so ever why.