I just found out that Groudon is the HEAVIEST pokemon i know.
It weighs 2094.4LBS!!!!!! Steelix is on 881.8LBS! You would need to combine steelix's weight with the 3 regi's to out weigh Groudon. I just found this out when i got too bored and started looking at the pokedex after the completed it.
wow who cares