Not sure who was the heaviest of all-time, but currently this beefcake tips the scale at 295... top of the pops in the MLB (circa, 2080).
Drafted 16th overall out of Texas Tech in 2061 by the Vancouver Whitecaps (now known as the Giants)... this big mamma jamma has 18 years of Major League service to his name with 1 World Series ring (with Vancouver in 2071)... he's led the league in plate appearances once, at-bats once (interestingly not in the same season that he topped in PAs), and RBI's twice, is a 12-time player of the week, 5-time player of the month, world series MVP (2071), and 3-time all-star... he collected his 1500th RBI and 3000th hit in 2078. He's scored 1500+ runs, has struck out 2,322 times, is an Aquarius, and likes to fish in his spare time - that is when he's not devouring Hot Fudge Cream Puff's at
Sanders Candy and Dessert Shops in his home state of Michigan.