Multi Target (spelled Multi-Target in BTD5) can make a Boomerang Thrower pop seven bloons (seven in BTD4, BTD4 Expansion and BTD5; five bloons in BTD2 and BTD3) instead of three bloons. The Boomerang Thrower gets three curved lines on its clothing in BTD5. The boomerang that is thrown remains unchanged in appearance.
In BTD2 it costs $270 (Easy), $305 (Medium), and $310 (Hard). In BTD3 it costs $230 (Easy), $275 (Medium), and $290 (Hard). In BTD4 and Expansion it costs $215 (Easy), $250 (Medium), and $270 (Hard). In Bloons Tower Defense 5 Mobile and Steam it costs $300 in Impoppable.
The Boomerang Thrower with the Multi Target upgrade in BTD4.
The upgrade button in BTD4.
A 1-0 Boomerang Thrower next to a 1-1 Boomerang Thrower in BTD5.
A Boomerang Thrower with Multi Target in BTD5
Multi-Target icon in BTD5
Multi-Target upgrade icon in BTDB Mobile