Whales - The whales would be the largest aquatic mobs and the second largest general mob behind the EnderDragon, they would be found in lower layers and only in large oceans and with low rarity in small seas etc, humpback whales and sperm whales could be added, they drop fish and possible items that were found in the sea like blocks, items etc. They are passive mobs and only attack when threatened
Lions - Lions would be mobs that can reach up to 2.5 blocks high and 1.5 or 2.0 wide, they would spawn only on savanna biomes, drop meat and attack other animals like pigs, chickens, wolves. They do not attack mobs like creeper, zombie or skeleton.
Seal - The seals would be animals that were born in only ice biomes near water, they would be passive mobs but if they were attacked they would attack the one who attacked, they could have up to 3 blocks in height and 1.5 in height, drop fish and do not attack mobs.
Bears - The bears would be mobs aggressive and could reach up to 4 blocks tall and 2 wide, they attack any kind of mob and live in biomes like taiga and forests, drop only meat.
Baleias - As baleias seriam os maiores mobs aquáticos e o segundo maior mob geral atrás do EnderDragon, elas seriam encontradas em camadas mais baixas e apenas em oceanos grandes e com baixa raridade em pequenos mares etc, poderiam ser adicionadas as baleias jubartes e as cachalotes, elas drop peixes e possíveis itens que foram encontrados no mar como blocos, itens etc. São mobs passivos e apenas atacam quando ameaçadas
Leões - Os leões seriam mobs que podem chegar até 2.5 blocos de altura e 1.5 ou 2.0 de largura, eles spawnariam apenas nos biomes de savana, drop carne e atacam outros animais como porcos, galinhas, lobos. Eles não atacam mobs como creeper, zumbi ou esqueleto.
Focas - As focas seriam animais que nasciam em apenas biomas de gelo perto de água, seriam mobs passivos mas se forem atacados atacariam o quem atacou, eles poderiam ter até 3 blocos de altura e 1.5 de altura, drop peixes e não atacam mobs
Ursos - Os ursos seriam mobs agressivos e poderiam chegar até 4 blocos de altura e 2 de largura, eles atacam qualquer tipo de mob e vivem em biomas como taiga e florestas, drop apenas carne
Ummm… Who cares if they add whales because "they are being threatened by whale hunting"? I mean if you are going to say how people will kill them and it will "encourage killing whales" then why don't you want villagers removed because people kill them and one could say that "encourages genocide"... I mean the whales don't have to drop anything they can just be for fun... not everything needs function somethings can be added just for fun and the looks rather then anything else.