if u have the key to the shark place, full team, water with e remote, and can move first, better go to shark place xD they drop food/books/2x pot/fun tokens/MSB/glazes, and they are the highest lvl mobs in this game (except the one in T.I.) so they give the best exp compare to others, if u're afraid they combo n spawn you, there is a corner that just has 1-3 spawn sharks.

pangolin is quite good as well but sadly they don't drop food like turtles xD, and if u're training low lvl pets there and still got spawned in usual place where rbs are training, just go deeper to the forest where the athena pre q is, and afk walking there, they just spawn maximum 3 pangolins.

if you can't survive in pangolin, you can try trees near hanging garden, they drop don't drop food but seeds (even mango seeds), their lvls are 100-103 if i'm not wrong (plz double check first, coz i don't remember their lvl :)) they don't hit too hard like trolls in japan, so less food needed, but becareful coz sometimes lvl 150 eagle spawn there, if u have a e-remote just make ur leader will run if encounter eagle o.O (need to put specific number on the HP slot)