Mountain

 is a Tier 5 Tank that upgrades from Conqueror and Mega Grower at level 60.

Design
The has a barrel like the Builder's, but where the Builder tapering tip would be there's a very short hexagon shape made out of 2 trapezoids placed end-to-end. Attached to that structure is the actual Builder tip from where it fires blocks.

Technical
The is extremely unique as its blocks are able to grow upon impacting each other. This consumes the newest-fired block and grows the older one.

Trivia
A similar tank called "Assembler" was released on 23/5/2023 in original arras, However, if you shoot an Assembler block at the old assembler block, it will be destroyed upon impact and the new block grows and gets dragged to the player's mouse. Assembler blocks from different players on the same team can also merge. It has a limit of merging 11 times, making 12 blocks merge into one.