The Thaumic Slime has similar parameters to its mundane counterpart: it moves, attacks and dies the same way, splitting into smaller ones. The only difference is that smaller slimes can stick together to form bigger slime again. When done so, the max health of the bigger slime will be the sum of the max health of the 2 smaller slimes that formed it. The damage will also grow the same way. The limit is 100 HP and 100 damage. The slimes of maximum size can be grown by any auto-spawning machine, they will stick together in one as long as the resulting slime stays in the spawn area.
Fully grown slime will still eat the smaller ones, even though it cannot grow bigger anymore.