Mini crawler crane designed I came up with (cat for scale) I used set 42121 as the base and the instructions for set 8288. The hardest part was setting up the pulley
Technicopedia: Cranes
BUILT) Lego 8288 Crawler Crane, Hobbies & Toys, Toys & Games on Carousell
LEGO 8288 Crawler Crane Set Parts Inventory and Instructions - LEGO Reference Guide