When they leap at you it's hard to see where they go, I recommend finding a corner and staying there until it leaps then bola and either kill or knockout. This always works for me when I'm trying to tame one but another tip, just stay out the swamps
For all the noobs out there, if these things kidnap you in the swamp, here’s what to do. Take out your bow/ gun. Pray you have ammo and fire right into its head. This strategy has saved me countless times.
P.S. If you have a strong melee weapon such as a pike or sword on you, that also works.