. ▁Despite ▁this , ▁he ▁is ▁able ▁to ▁use ▁the ▁knowledge ▁he ▁learned ▁to ▁guide ▁them ▁back ▁to ▁the ▁Great ▁Valley . ▁ ▁The ▁character ' s ▁only ▁appearance ▁in ▁the ▁films ▁was ▁in ▁The ▁Land ▁Before ▁Time ▁VIII : ▁The ▁Big ▁Free ze , ▁but ▁he ▁is ▁regularly ▁seen ▁in ▁the ▁TV ▁series . ▁ ▁Mo ▁Mo , ▁vo iced ▁by ▁Rob ▁Paul sen , ▁is ▁a ▁color ful ▁O ph th alm osa urus ▁who ▁first ▁appeared ▁in ▁The ▁Land ▁Before ▁Time ▁IX : ▁J our ney ▁to ▁Big ▁Water . ▁The ▁character ▁is ▁b iling ual , ▁speaking ▁a ▁broken ▁form ▁of ▁the ▁her b iv ore ▁language , ▁as ▁well ▁as ▁his ▁native ▁dol ph in - like ▁language . ▁He ▁is ▁very ▁play ful , ▁and ▁becomes ▁popular ▁with ▁the ▁main ▁characters ▁aside ▁from ▁C era , ▁who ▁is ▁at ▁first ▁anno yed ▁by ▁his ▁play ful ▁ant ics . ▁ ▁Though ▁the ▁character ' s ▁only ▁prominent ▁roles ▁are ▁in ▁the ▁nin th ▁movie ▁and ▁in ▁the ▁TV ▁episode ▁" The ▁Miss ing ▁Fast - W ater ▁Advent ure ", ▁he ▁has ▁made ▁a ▁few ▁appearances ▁in ▁the ▁films . ▁In ▁The ▁Land ▁Before ▁Time ▁X : ▁The ▁Great ▁Long ne ck ▁M igration , ▁he ▁j umps ▁out ▁of ▁the ▁water ▁during ▁the ▁" Ad vent uring " ▁musical ▁number , ▁and ▁he ▁says ▁" And ▁fly !" ▁during ▁the ▁song ▁" F lip , ▁F lap ▁and ▁Fly " ▁in ▁The ▁Land ▁Before ▁Time ▁XII