When you mentioned that it might be guarding something else I thought I'd mistaken reggigigas for regirock. I like trainer oriented entries so I really liked this one. I like to think a slowking could talk in english though.
I have:
Platinum
Heartgold
White
Black
Rumble Blast
White 2
I used to liek mudkipz, then I took an arrow in the knee. However the arrow turned out to be a seaking. It yelled "F*** yeah" so I screamed "FUUUUUUUUUUU!!!!". The seaking's face became that of a troll while mine became forever alone. The situation was super effective.