Cougar (35t)
Model by Primus

Following her Clan's Trial of Refusal against Clan Wolf in 3057, Khan Marthe Pryde of Clan Jade Falcon wanted to bring new and deadly OmniMechs to the field of battle. Knowing she had already taxed her Clan to the limit in the conflict with Clan Wolf, she took an unprecedented step. Rather than building a new OmniMech from the ground up, she assigned the Jade Falcon scientist caste the job of modifying a proven design into an even deadlier war machine. Beginning with a stock chassis from a Clan Adder (designated Puma by Inner Sphere forces), Clan Jade Falcon scientists managed to field a virtually new design, code-named the Cougar, in roughly half the time normally required to construct and test a new OmniMech. Jade Falcon technicians gave the Cougar more pod space to allow for a greater variety of larger weapons. To accomplish this, they replaced the 210 XL engine with a 175 XL model. The overall consensus was that the increased firepower more than made up for the new 'Mech's slower movement rate.

Source: Technical Readout 3060
19 tons pod space availible