wait to see if it comes out on its own..hippo likes to wedge themself in tight places when scared or sleeping..if its clearly stuck maybe just pick up the rock and gently shake it in the water????....
Mine too goes into the most smallest spaces btwn rockwork and i know one day he will get stuck and ill be pissed off if i have to take apart my rockscape...lol
goodluck getting ur guy out. Has he being eating since you have had him??
Mine usually sleep/rest in the rockwork when the moonlights are on, wedged between rocks. I thought they were stuck a couple times. Then they come back out when the lights are on.
How long has it been in the rocks? I wouldn't bother it if it has only been like 12 hours. It may come back out on its own, otherwise you might have to take the rocks apart a bit to help it out.