Just Derek getting dragged into large dergmaw scooped UNDER the large tongue doing his best to fight out before the maw closes but with the tongue curl around him there was no slipping free. Getting dragged further in and getting pinned to the squishy slobbery bottom of the dergmaw, buried under the heavy weighted tongue as the maw closes up tight, sealing the squirrel in place.

Such a thick tongue any squirm or struggle or push just sinks into the squishy muscle, and wriggling only appears as a slightly squirmy underjaw bulge. Pretty much an airtight almost vacbed smothering between bottom of the tongue and the lower jaw, nothing but slimy warm and soft flesh all around the whole body, absorbing all struggles as if they were nothing, leaving the squirrel as nothing but a slightly squirming underjaw bulge for as long as the derg desires....

...and knowing that he loves overkill and long term, worried he would put a muzzle restraint purposely on himself to make sure the squirrel never moved from his tonguesquish containment ever again.

Art by  akudrache
Featuring  dereksquirreltail