Bring about 60 tranq darts if you want to tame a max level megatherium get 4 metal bill boards place 3 in a box formation keep one and hit the megatherium then RUN FOR YOUR LIFE wait till he aggros on the bill board then go around and place the 4th bill board behind him then he's trapped so start shooting away he'll take about 10 prime meat only if you let him drop like 800 hunger this is in small tribes BTW.